Originally Posted by jimlab

And how would that keep companies from producing parts that look like racing parts but provide little or no measurable benefit?

F1 cars use spoilers front and rear to produce downforce. Does that make a VeilSide body kit a performance improvement at high speed because it has front and rear spoilers, or is it just an appearance change that may or may not be stable at high speed, and in fact could be dangerous at high speed? Only a wind tunnel knows for sure.

If you're going over curbs, you have more to worry about than disturbing the air...

Originally Posted by PVerdieck

F1 and road course cars regularly use curbs as part of the track at certain points.
Curbs being not what you see on our streets, but the sloping red and white striped concrete sections present on the inside of certain turns and chicanes.