Ways to tell an unmarked cop car in your city/area/state?

[cl94]

A really good way in the Northeast is the presence of an orange E-ZPass. Every state I know of in the E-ZPass region has them and they are typically only given to emergency vehicles. A spotlight is a dead giveaway. Municipal plates of some form are a pretty good sign, as New York cop cars never have regular plates (if they have plates at all). Look for missing hubcaps.

An Impala with weird antennas is also a good sign. Detectives often drive those.

I have seen Massachusetts cops on the Mass Pike driving Jeep Cherokees.

[SP Cook]

Not sure I have ever seen official vehicles in other states with orange E-ZPass transponders.

In WV state cops, turnpike owned vehicles and government ambulances have orange EZ passes, which I think just work as a "free pass".  Other government vehicles, including local cops, have blue which get billed back to the agency or county. 

One of the insider political perks is to get on the turnpike commission.  After a year on said do-nothing board, you get an orange transponder for life.

[jeffandnicole]

A really good way in the Northeast is the presence of an orange E-ZPass. Every state I know of in the E-ZPass region has them and they are typically only given to emergency vehicles. A spotlight is a dead giveaway. Municipal plates of some form are a pretty good sign, as New York cop cars never have regular plates (if they have plates at all). Look for missing hubcaps.

An Impala with weird antennas is also a good sign. Detectives often drive those.

None of this is true for the 'entire' Northeast EZ Pass region.  NJ doesn't use orange EZ Passes as far as I'm aware.  I can't recall seeing orange EZ passes in PA, DE or MD either.

Impalas are also used on a state-by-state, town-by-town basis.

[PHLBOS]

In the Crown Vic days the dual exhaust of the CVPI was enough to give me pause. I know there were civilian variants in the later years that had them too, but they were few and far between. If I saw 2 exhaust pipes I wasn't passing them for nothing, no matter what else I saw or didn't see on them. If I saw 1 pipe, I motored on by. Never got pulled by a Crown Vic with one pipe, so it worked for me.

Note about the black grills and nicer wheels. My department never had a black grill, steel wheel with center cap type either. Even our marked units had the regular chrome grills and whatever decent base model wheels was offered for that model year.

The CVPI (aka P71 for most vintages) offered what was known as the "Street Appearance" packages that basically added the chrome grilles wheel covers (and maybe pinstripes) to the cop car so it would look more like a civilian Crown Vic.

It wouldn't be the first time some police forces used slightly dressier models/packages.  Back in the late 60s/early 70s; the South Carolina Highway Patrol used the slightly dressier Galaxie 500 over the more commonly used (by police forces) Custom & Custom 500.

[paulthemapguy]

The color scheme on the New Hampshire police plates is so different than the general plates that they're remarkably easy to spot:

In Illinois, marked municipal police vehicles will have a license plate with a vertical "MP" along the left side, just like this.

Unmarked police cars in Illinois will have a license plate with green text on a white background, and the plate number will be "M ### ###."  Municipal and county agencies will also use these municipal plates for construction and maintenance vehicles as well, plus government-issue vehicles for local officials.  So if it's got an M plate and it doesn't look like a work truck, it might be a cop.

Also, I don't think cops ever use the "U" plates for state vehicles.  "U" plates are only for state government operations.  I've never seen a cop use one, anyway.

[Brandon]

The color scheme on the New Hampshire police plates is so different than the general plates that they're remarkably easy to spot:

In Illinois, marked municipal police vehicles will have a license plate with a vertical "MP" along the left side, just like this.

Unmarked police cars in Illinois will have a license plate with green text on a white background, and the plate number will be "M ### ###."  Municipal and county agencies will also use these municipal plates for construction and maintenance vehicles as well, plus government-issue vehicles for local officials.  So if it's got an M plate and it doesn't look like a work truck, it might be a cop.

Also, I don't think cops ever use the "U" plates for state vehicles.  "U" plates are only for state government operations.  I've never seen a cop use one, anyway.

State troopers will use U plates from time to time.