Names for coroplast
 

Just thought I would add this so it might help people doing searches!

Corrugated plastic is called Coroplast in the USA

and Correx in the UK (and ? Europe)

and Corflute in New Zealand (took a lot of searching to find that)

This is helpful for international members trying to take their MPGs to the next level!

Sorry for a noob question, but is this the stuff that they make election signs out of?

Yep, a couple members have used old election signs for their aerodynamic modifications

Not to change the topic at all, but I used a thick strong flexible plastic material for my forward underbody cover. The material I used is the same material used inside mobile homes, and also used as shower wall covering. It's sold in 4'X8' sheets at home depot. One side has smooth but not glossy, the other side is glossy but has a very rough texture. I had to use a jig saw to cut it, it's too thick to cut with a razor. One 4'X8' sheet weighs about 8 lbs. It's about 3/32" thick.

That is the stuff I used for my fender skirts.