Originally Posted by ausf

There is absolutely zero issues with the kit fenders or track guards. You are much better off using them over PE (especially for track guards) since the glued styrene bond is so much stronger than you can get with brass unless you're globbing on epoxy.

Anything you can do to damage or bend PE can be done to plastic (this example is 1/35):

http://ausfwerks.com//techniques/fender/main.html

Even if you want missing guards or fender pieces, it can be done with good planning and a sharp blade.