Actually, this is going into production on some MB'* and Infiniti'*. They call it "Reactive Accelerator Control" and it is a difficult technology to describe. I read it in a Motor Trend from last year. If I find which issue it was, I'll get permission from them to link or post it here.

could i aim the lasers to refect off of the rear glass of the car?

Depends on the wavelength of the laser and the angle of the glass. You want as near to a 90° incident angle to get a good return instead of a bunch of scatter. It'* kindof a tricky proposition, but a person with the right knowledge could build this in his garage and integrate it into the CC. I wouldn't aim at a window. I'd be looking at the back of a trunk lid or bumper, or both. Licence plate is too small a target on a moving vehicle.

I was just trying to think of something that is close to the same position on most models of cars. I think you would have to have the lasers mounted on diffferent parts to make up for this factor. The whole thing still sounds a little tough unless we can get a programmer...

A couple of things to consider on this:

1. Are there any FCC issues with using lasers in this way?
2. What is the chance they will set off anyone with a laser detecting fuzz buster?
3. how are you planning on keeping the emitters free from dust & dirt?
4. Would this be easier if you simply used sonar, like a modified fish-finder?

Depends on the class and power of the laser. No FCC issues regarding Lasers that I know of. Nobody uses lasers for communication, at least not commercially (it is possible to transmit sound with pulses of light....I've done it in a lab...not fiber optic, actual exposed beam).

Setting of a Laser detecter would be wholly dependent on the wavelength. I'm not sure what the detectability bandwidth of a typical laser detector is, but it would be easy to work around that.

Keeping the laser aperture clean is simple. You don't expose it unless the system is running. Most lasers in commercial applications are transmitted through an optically coated flat window as a final barrier against the elements. Keep the window clean by wiping it off when you wash the car.

Sonar doesn't work too well without water as a transport medium. Kinda like a fish out of water. You'd have to go radar, and good luck getting a license for that. The potential lawsuits are unimagineable.

It'* far-fetched, but it'* possible, and I think lasers are the best pick for a detection device in the speed/distance category.

I'll defer to you on this bro. Your lab experience trumps my pittiful scope of knowledge here on this topic.

I dodge photons daily. Laser tag takes on a whole new meaning here.

Well for me, I love to keep my foot in the throttle sort of speak...just sitting there following the bozo in front of me SUCKS...remember...If your not the lead dog...the view never changes!!!

How about using a beefed up version of those thingies that they put on the rear end of cars so people know how much room they have when they are backing up? I have seen some on the front of a few cars, maybe if we made it a little stronger would it work???