I've been trying to search the forums all morning but can't seem to find anything about it. Perhaps using wrong keywords. However I have a nismo exhuast that has been extended to fit however I haven't extended the tips yet. So it is tucked underneath the bumper. Overtime its leaving a brownish mark on my rear bumper around my diffuser area (I have an IP coupe so it looks horrible), I am assuming its because of the test pipe combo with the exhaust. I plan to possibly get an aftermarket diffuser and have it painted black to cover it up.

My question is, if I do extend out the tips, will the resin or whatever you call it cover more of my bumper? like past my diffuser line area (therefore having a diffuser useless)? Cause I saw pictures of extended tips on coupes and IMO it looks like it will be spread out more by the way the bumper is designed or will it stick far enough that it will not harm the bumper anymore?