This weekend im gonna take out the inner fender lining to roll my fenders ... can i leave that off or is there a good reason for it to be put back on?

 

if you have or plan to have cold air intake you need it to keep tire debris away from the filter. past that, ive seen it left off but i would personally never do that

 

Theoretically, they help the aerodynamics of the car by controlling air movement from the tire and from under the car, but they're really just there to keep the dirty **** out. I personally don't ever keep mine.

 

if you can keep them in place do so..unless you don't drive much in rainy muddy conditions. It can throw debris into the fender and door jam/hinges and can get things messy if you show a ride.
that the main disadvantage I know of once it's removed. Good luck w/ your rolling..

 

Thanks for the replys...ill try and keep it on if i can...