On 3/3/16, jim bell <jdb10987@yahoo.com> wrote:
>Plates and lights leaves left only how much beams back from
>micro scratches in windshields?

Probably very little.  The emitted laser power of the unit I had the documentation for

emitted 15 watts.  Most of that would have hit the car, but only a tiny fraction would

have been reflected back to the laser gun.  Google search "Lambertian".    

https://en.wikipedia.org/wiki/Lambertian_reflectance   (The reflectance of a piece of

white paper is primarily 'lambertian':  It doesn't act like a mirror;

nor does it act like a retroreflector.

>And of course that even consumer flat black spray paint
>seems to still return some fraction of a real laser beam.

I didn't and don't expect that anybody was going to re-paint their car for this

purpose.  Disabling the retro-reflectors is relatively easy.  

>Some locales do have laws regarding plate visibility and
>or modification [via overlays / surrounds].
>And some makers do advertise those 3M-like structures
>in their plate cover products, some even specifying visibility
>width angles in degrees.

I understood that some of these modifications might arguably be called in 

violation of the law.  The main one, covering the license plate, seems

to be a minor issue.

>But the headlight / retroreflector thing is uncaptured market
>at the moment. So like with the plate guys, you should go
>for it if you can solve the problem of production for and
>application to all the 3d shapes of those lights / retros on
>vehicle models.

I don't know how big the laser radar market currently is.  When I did the 

research in 1990-91, it was not clear how big an issue it would eventually

be.