Actually, the retroreflectors used for survey work are rather expensive
(been trying to find some for under $200/ea for some time now).

It's quite easy to make 'corner cube' reflectors from readily available
mirror tile, and string them along your roof line. (cut 3" squares and
use silicon sealant at the joints).
The problem is that the amount of energy reflected is only a small
percentage of what the inconsiderate driver is using against you.

You'd be far more 'effective' if you had a rear facing spotlight, and
just turned it on when the trud annoyed you. He'd get the message since
he'd have to back off to aviod being blinded.

As for legality, "I'm sorry officer, I didn't realize that I'd bumped
the switch for my supplimental back up light".

"Peter L. Peres" wrote:
>
> >Hey I have been pondering making a transmissive LCD array into an on/off
> >mirror that I could mount into the back window of my car to reflect back
> >the light of the $%^& who has his headlights too high behind me. I had
> >been wondering how to have the mirror dynamically self focus on the
> >driver, now I know. Perhaps I really should have changed the subject to
> >[PIC] after all.
>
> Just place a row of catadiopters on the front collision bar. The 2 inch
> ones used for theodolite survey work will do fine. You don't need to
> orient them, they return the glare where it came from. I also suspect that
> this is not legal so I did not say that you should do this. I.e. don't do
> this.
>
> Peter

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