With them on, you'd get less turbulent air inside the wheel well, and better protection from rocks and debris, without them, you'd get a bit less air pressure built up inside of them, less of a need for fender vents?

 

I never did. debris protection isn't much of a concern to me, and while there may be some benefit to turbulence, the sheer irritation of having to deal with those things every time I changed a fender would have annoyed the hell out of me.

 

I just yanked all mine out on the FB this past weekend. Did not weigh that much but they started to irritate me too.

 

Fair enough, thanks guys. If I decide to run them again someday, I'll probably fabricate new smoother ones.

 

Never had them as the car came that way.
The only odd part is picking out track rubber -- from the slit between the fender and the door.