Assuming you’ve heeded my warnings and seriously decided you want to pursue creating an antique police “tribute” car, here are some suggested steps based on my experiences:

1. Get this book – Pick up a copy of Police Cars: Restoring, Collecting and Showing America’s Finest Sedans by Ed Sanow – This must certainly be THE definitive book on the subject of restoring, collecting and showing police cars. If I had had this book when I first started restoring this antique squad car, I would have made some better decisions and done things much differently — like, saving money! If you are involved, or want to be involved, in restoring or showing old squads, this is definitely the best starting point I have found. This book is a MUST HAVE for anyone involved in restoring, collecting and/or showing an old police car
2. Document everything – Starting right now, get a binder (notebook or whatever) — or start an online weblog (“blog”)! — and keep track of each step. This will help keep you on track and provide a nice record of the entire project when it is finished.
3. Finances – Work out the finances. Determine what you can afford to invest in this endeavour. Divide that number in half, then divide it in half again. Because that’s about all you have to start with. Unless you get very lucky, this type of project will “nickel-and-dime” you to death.
4. Accuracy – Decide how accurate you want to be in your antique police car. Cars that were actually used as police cars are often “handed-down” to other government agencies, then sold and used as taxis or — heaven forbid! — demolition derby cars. So if you find a real antique police car, it will likely be either a rotted-out hulk, or an immaculately restored (i.e., expensive) show car. A clone or “tribute” car does not have to be an actual police car, and they are easier to find in decent condition for a fair price. They usually don’t have the big “police” engines, however, so you are giving up some serious authenticity.
5. Choose a department – Now that you’ve got a basic idea of where you want to go with your new hobby (passion?), determine what department and year you want to emulate. Your decision may be influenced by what year and make of car is available, or by a personal fondness for a particular department. Keep in mind that California Highway Patrol (CHP) and Chicago Police Department (CPD) vehicles are pretty common, so if you choose one of these your car will certainly not be very “unique.”
6. Choose a vehicle – If you decide you want to emulate a particular police agency, start by determining what make and model of vehicles they used throughout the years, then look for an appropriate vehicle. For example, many departments used Mopar (Plymouth Fury, Plymouth Belvedere, Dodge Polara) or FoMoCo (Ford Custom Fordor, Ford Galaxie, Ford Crown Victoria) vehicles. But you will find the occasional use of non-typical “police-package” vehicles (such as Oldsmobiles or Pontiacs), particularly in small-town departments.
7. Verify the legality – Don’t wait until you’ve completed the project, and invested thousands or even tens of thousands of dollars, only to find that the thing is illegal and the police are confiscating the car and throwing you in the slammer. Some departments, or local or state governments, are very protective of their image (as well as being seriously concerned about police impersonation).
   • I have heard of one state that uses a custom paint color for their state police vehicles, and has outlawed the use of that color on any non-police vehicle.
   • Another state uses a two-tone color scheme — in factory colors — for their state police vehicles. Supposedly, if you paint any non-police vehicle in any two-tone combination using those same two colors, even if the layout is completely different, the car will be seized and you will go to jail.
   • Another police agency has copyrighted or trademarked the markings on its vehicles so that if you replicate the markings they can come after you under civil law (in addition to criminal law for “impersonation”).
8. Research – Once you’ve determined the department and year, research! See what you can find out about what type of vehicles they used, their paint scheme, radio, siren and lighting equipment, etc. You can contact the actual department and ask for information, or remember that “Google is your friend.” For example, try http://images.google.com and specify the department name, as in this example: “Illinois State Police car”. Keep in mind that you may get images that don’t apply, or images of inaccurate toy or other reproductions. But at least it’s a place to start. And keep in mind that the older the year, the more difficult it will be to locate the proper equipment. (Twenty-year-old police radios, for example, are being dumped for cheap all over; sixty-year-old radios are difficult to come by; older than that, finding one is a once-in-a-lifetime stroke of luck.)
9. Finalize your selection – Now that you’ve researched the department, the vehicle, the availability of equipment and the legality of this endeavour, it’s time to make sure you really want to proceed. If so, document your plans and what you need to make this happen.
10. Locate and purchase – Track down the chosen vehicle year, make and model in an acceptable condition. This will likely be the hardest part.
11. Restore – Time for any needed bodywork and paint. Be sure to take lots of photos of the process at various stages! If done right, the restoration work should take quite some time, so now you should start working on the details…
12. Equipment and incidentals – Now that you have the vehicle, you should start looking for the equipment you discovered during your research step. Think of everything you would expect to find in a police car of that vintage and from that department or agency. This might be as hard as locating the proper vehicle; maybe even harder. So start while the car is being restored; don’t wait until it’s done. Here are some of the things you might want to look for:
    1. External equipment:
       1. Light(s) or lightbar
          1. roof-mounted
          2. rear-deck or trunk-lid mounted
          3. front fender-mounted
          4. grille-mounted
          5. spotlight(s)
       2. Siren speaker – roof-mounted, behind grille, on front fender, etc.
       3. Antenna(s)
          1. roof-mounted?
          2. fender-mounted?
          3. type and size?
       4. Vintage police-style or YOM (year-of-manufacture) license plates (check your laws!)
    2. Internal equipment:
       1. radio(s)
          1. control head under dash
          2. transceiver (transmitter/receiver unit) in the trunk?
       2. siren control
       3. light controls – could be a fancy control unit on newer cars, or simple switch(es) on older cars
       4. prisoner cage for rear seat (rare on “antiques” and may be a concern to local law enforcement)
       1. miscellaneous display equipment in the passenger cabin (be careful to avoid “impersonation” concerns!)
          1. handcuffs (with key if they are functional!)
          2. baton / billy-club / nightstick
          3. whistle
          4. flashlight (possibly with traffic director red/orange cone)
          5. ticket book with appropriate style clipboard or other holder
          6. uniform patch and badge and similar – preferably in a sealed display case
          7. uniform hat
          8. uniform
       2. miscellaneous display equipment in the trunk
          1. fire extinguisher
          2. first aid kit
          3. blanket
          4. jumper cables
          5. tire iron
          6. foul-weather gear (raincoat with hat cover, boots, umbrella, etc.)
          7. emergency gear (ax or hatchet, riot gear, etc.)
13. Markings – Now is when you will want to have the external markings made. These could be decals, magnetic signs, or in very rare cases even painted on. If possible, do not put them on the car until you have completed the CYA step, or at least are ready for the Appraise step, both below.
14. Store it – Stop driving the vehicle! At this point, you are driving what is increasingly looking like a police car. This is when you are going to start to get noticed by the real authorities. Store the car in an enclosed space where you can work on it, and keep it there until you have completed the CYA step, below.
15. Equip – Start decking out the vehicle with the equipment you hopefully have already located. Again, refer to any photos you have previously located and/or your contact at the agency for proper placement of lights, antenna, radio, etc.
    • Keep accuracy in mind, but consider allowing for a little variance. For example, maybe a large, “buggy-whip” style antenna was mounted on the side of the rear fender of the real cars back in the day. But that location can lead to a lot of bruised hips in a tight storage location — or car show with little space between the vehicles.
    • Sometimes vehicles were configured differently depending on their intended use or location. For example, a state police car assigned to a large metropolitan area might have its high-beam headlights replaced with red “wig-wag” (alternating) flashers. (The thought being that the additional warning capability was more useful than high-beam headlights in this busy metropolitan environment, whereas in a rural environment the opposite would be true.)
    • Many departments were not real consistent from one installation to another, so you probably don’t need to be either. In fact, two identical cars might come out of the equipping facility configured differently simply because they were completed by two different installers!
    • The bottom line: Accuracy may be important, but there were inconsistencies in the originals, and it’s still your car, after all, so feel free to take a few liberties.
16. Create signage – It is common for show cars to display some sort of poster or placard with details about the vehicle — its history, restoration process, etc. Think about what you’d like to have on yours, lay it out and have it printed. You can work on this while waiting for the appraiser (see below) to show up.
17. Appraise – This might be a good time to have the vehicle appraised. You’ve probably got a sizeable chunk of change invested; time to protect that investment. Get a professional appraisal and turn it in to your insurance agent. Keep a copy for yourself in a safe place.
18. CYA – Now is the time to take steps to assure the real police that you are not attempting to impersonate a police officer or a police vehicle. I list a few of my steps on the FAQ page. Talk to the local police and cooperate with them fully. Answer their questions. Follow their instructions. Heed their advice.
19. Photo – The car will probably never look better, so now is a good time to take a few photos. Find an appropriately scenic location, but be careful to follow those “CYA” steps!
20. Assemble the documentation – Now is the time to “finish” the binder documenting the project so that you can show it in all the car shows you’ll be attending. You might want to leave room in the back for photos and other documentation of shows you attend; or maybe start a new binder or album for that purpose.