When I was with the Herzberg Institute of Astrophysics I use to play around
with RAM (though we never called it that, likely because we were doing radio
astronomy not macho defense stuff :-) and often thought of coating a car
with it (sigh, to be ninteen again).  You'll want the graphite embedded
paint if you're considering going this route (Eccosorb Inc., Chicago? makes
an extensive line of absorbing material).  Make sure it's spec'd for the
appropriate bandwidth, that you put on a good 1/8" thickness, and that
you're prepared to live with the ugliest car in the world - she'll be flatte
black.  For all your effort you'll get a max of 3 dB attenuation.  If you're
cursed with a car with a flat front part i.e. upright radiator, this isn't
for you.  Nor could you mount the pyramidal absorbers appropriate for X and
K band wavelengths; though _extremely_ effective, they'd be much too long to
be practical, they couldn't take the beating administered to them by your
forays beyond the speed limit.  Besides, your car would look almost as
stupid as the the Chrysler Laser I saw last night that was decked out to
look like a Lamborghini Countach, complete with the spoiler, painted-on
intake scoops, and an obscene shroud that obstructed one's rearward view -
some people!
	

There has been some discussion about destroying radar guns, and I don't
know if I saw the complete thread, but I thought I'd throw in my .02
worth.

I do know of someone who did build a radar killer using a surplus
magnetron.  He was able to test it because he also worked at a facility
that repaired the guns.  As someone posted earlier, it would take out
the diodes on the front end, but nothing more.  After testing it, I
believe it was then dismantled for obvious reasons.  Don't ask me for
any more info on this, because a) I don't know any more and b) I am not
at liberty to discuss any other details.

> A reasonably large magnetron feeding a reasonably large antenna on the
> front of your car, wired up to a bank of capacitors charged by an
> inverter from the car battery, might be able to emit a pulse of 10 GHz
> or 24 GHz of sufficient magnitude to blow the mixer diode in the typical
> cop radar to glory-be.  You'd clearly want to have it trigger off the
> radar detector mounted next to it, but shielded from it in some way.

Reliable rumor has it that some folks did just what you are
suggesting, but instead of the magnetron they used a spark plug!  The
spark plug was mounted in a tuned cavity which was in turn coupled to
a horn antenna.

Back in the early days of police radar, they filled the back end of an
automobile with capacitors (and in those days there was a lot of room
in the back of an automobile), charged up all those capacitors, and
then, as they drove by an unsuspecting "target", they discharged the
capacitors all at once through the spark gap.

They left more than a few radar operators scratching their heads,
wondering why their radar unit suddenly failed, but decided to curtail
their activity before someone associated the failure of the radar
units with the loud shotgun-like bang that happened whenever they
threw the switch on their spark gap!