What plastics for front airdam...?

[euromodder]

Originally Posted by fjasper

You mean something like this?

I think you can find this stuff sometimes (used) at recycling yards.

Yes, conveyor belt rubber would do.

Stiff, but it'll still give way when that's needed.

[mcrews]

The Home Improvement produvt that is used over here is called:
garage door top and side seal
a neoprrene rubber 1 3/4 inches wide.
by Frost king # sg30wh
it is firm enough to hold it's shape but gives when in contact with something.
just a quick thought given your pic:
fashion a piece on each side the wraps up from the spoiler you have to pertrude wider than the tire. Then use the above product to get lower without sacrifing your suspension travel.