Why not use this for undertray wheel deflectors & fairings?
 

http://www.drillspot.com/pimages/269/26977_300.jpg

Cut off the corners diagonally, making inverted ramps, to attach to the underbody of the car in front of each wheel. The same application behind each wheel would act as a fairing.

Each of these $5.37 polyethylene trash cans would make two deflectors.

Tough and resilient, these would resume their shape after hitting a curb.

You can get a roll of 14"x25'x.19" thick aluminum roll for $15 at Home Depot.

Do it :thumbup:

I've had to stay out of the plastic tub isles for the past few months... I always try and re-purpose the shapes :p The last thing I did was use a trash can for a knight helmet and some other random thing for vambraces (for the same costume) :D

If you're by a university - I suggest some dumpster dipping around move out time.... You'll find plenty of those :thumbup:

Is this stuff stiff enough to be used without backing? Can it be readily used for undertrays, or must you add stiffeners?

Alu. has excellent heat dispersal characteristics, so is very good around heat sources such as exhaust pipes. Could make noise, though.

How about a sandwich panel using this alu. and Coroplast? Do the undertrays with Coroplast, and add alu. sheet where needed as a heat reflector/barrier.

What sort of adhesive could be used for a Coroplast/alu. sandwich panel? Silicone bathtub caulk?

How easily can the molded shape of these PE things be modified with a heat gun?

I've also been looking sideways at wife's Tupperware. They make some potentially useful oval stuff that, cut in half, would make great streamlined wheel fairings. Google for "oval Tupperware."

Ok, the 0.019" will actually develop cyclic fatigue cracks on the front, so far it is holding up on the back.
I would like to know how to laminate it also.

OTTO, i am trying to visualize which way you want to divert the air around the wheels, and how you are going to keep the air where you want it.

Yes, my bad.