Is it Illegal to Paint Your Car?

Is it illegal to paint your car a different color (with a non-reflective paint)? Supposedly the police want reflective coatings for radar (speed detection).

No it’s not illegal so go ahead and rush on down to paint shop and buy some B2 stealth coating with your tax rebate check . And why not throw on a cloak on invisibility while you are at it.

Nope. Radar speed detection reflects off the metal the car is made of - failing that, the chassis and engine block. Paint will not do squat.

Laser speed detectors require reflected light, but don’t need much of a return to measure speed. Maybe if you used the new “darkest black” material that absorbs 99.99% of incident light, but good luck getting your hands on enough to paint a car.


I’ve never heard of anything illegal about painting your car. Hell, I had an old car that wore down with age to a hideous matte finish and got plenty of speeding tickets. Perhaps you’re confusing it with reflective sprays for license plates, which prevent red light cameras from capturing your plate number.

And even then, the laser makes the most use of the retroreflective properties of the license plate and/or light housings, especially headlights. So eliminating laser reflections from paint is likely to do nothing.

And to the OP, there’s no validity that any government or police force wants to see you have glossy paint for purposes of radar measurement. That’s because it doesn’t make a difference. The shape and contruction materials of your vehicle are all far more important than the surface coating (i.e. paint). Giving yourself a matte-finish paint job will have zero measureable effect on your car’s radar return.

Suffice it to say, if achieving radar invisibility was as simple as slapping on the right paint, lots of engineers who work stealth for a living would have been out of their jobs a long time ago.

That B2 stealth coating MIGHT be illegal on your car.
Apparently the formulation on that was (maybe still is) toxic.

If you have metal wheels that spin (and headlights, license plates, etc) your car will show up on radar. Paint away.

And even that really doesn’t work, does it? I’ve always been under the impression that these things were just snake-oil for your car.

Plus it washes off in the rain :smack:


Come to Houston this spring for the Art Car Parade. (The first in the country!)

Some of the entries are fragile concoctions, dreamed up for the Parade–but others are street legal. They might be repainted–or covered with broken mirrors, Mardi Gras beads or living turf! However, none of them will help you escape notice.

Mythbusters did this recently. They concluded that none of the methods popularly touted for obscuring your license plate from the cameras had any noticeable effect.

They are money-sucking crap in a can. Mythbusters did a segment on these and other speed camera myths. They did exactly jack squat.

Even if you did manage to get hold of the special coating used for stealth aircraft like the B-2, it wouldn’t do a thing for you. For one thing, your car has a shape which is pretty good at reflecting radar emissions back to the transmitter. Even if it weren’t, the coating doesn’t completely absorb the radar, it merely attenuates it. At the range traffic radar is used, there would still be enough of a reflection to give a good reading. My 50cc scooter is small, and has plastic body panels but radar can STILL pick me up at about 30 yards. Metal isn’t the only thing that reflects radar. Most materials can, to some degree or another. Even plastic and glass

I prefer cleverly placed leaves in the Fall, or mounds of snow in the Winter. During Spring and Summer I drive like a responsible person.

And as of the beginning of this year, the use and sale of those are illegal in California. Also illegal are the “fresnel” type license plate covers that are intended to obscure your plate:


But nothing saying you can’t paint your car whatever color you want, or even emulate a DeLorean and sand off all the paint.

The only requirement I know of regarding paint is that if you buy an old state police vehicle through the surplus auction, you have to sign an agreement that you’ll repaint it to be any color but blue. They don’t want bogus state troopers about.

Did we really need Mythbusters to figure this out?

I remember being told 15 years ago that you could use such things to evade photo speed traps. What I kept asking, and what the guy could not explain, was this; if I can still see your license plate number WITH MY EYES, why wouldn’t a camera be able to see it?

One possible explanation was that they’d fire a flash when taking your picture. If you could reflect back the strobe light from the flash differently then normal natural light it would obscure the plate while the picture is being taken. Like if you take a flash picture of a traffic sign, the reflective parts are completely washed out.

Back to the OP:

One thing you may have to do is change the registration to reflect (pun intended) the new color.

I, for one, withheld judgment on this issue until I saw that episode. Some plausible ways those blocking filters could work (that is, plausible if you haven’t seen the Mythbusters episode and/or don’t know how the traffic cameras work) include:
[li]Difference in wavelength. Maybe the traffic cameras use IR or color filters.[/li][li]Angle. Maybe the traffic cameras are at a specific height, and some lens system may make it difficult to see from that angle.[/li][li]Contrast. I can read plates with those filters on, but not as easily as uncovered plates. Maybe that makes enough difference.[/li][li]Lighting, as mentioned by Telemark above.[/li][/ul]

And IIRC, one of those devices did make several characters on the license plate illegible. Of course the remaining characters were still enough to identify the car.

I’m pretty sure they do use IR.

Anyway, my OP seems to come from a fairly widespread myth. I’ve heard that it is illegal to paint your car (or paint with non-reflective coating) at least in certain states. Thanks for the info.