OK, a little off-topic, since this pertains to my wife's 135i, but potentially applicable to FFR's aero parts. I trust the experienced opinions of forums members here more that random google searching, so hopefully someone can weigh in...
My wife got rear-ended this week, luckily it was a minor impact with just cosmetic damage to to rear bumper cover and carbon fiber diffuser. This is an OEM BMW part I installed which replaces the lower rear valance. I'm sure it's pretty ineffective aerodynamically, but looks much better than the stock gray plastic (see image of part below).
She took it to Amato's (a great body shop in SD) and got an estimate of $2700 to replace the diffuser and paint blend the damage on the bumper cover. Even they suggested taking the check form insurance not bothering to repair. I'm not going to do anything to the paint except polish, since at some point the bumper is sure to get more damage. However, I'd like to repair the scratches in the c.f. some are deep enough to require filling for a proper repair (the part is not cracked, and it's not structural, so they're no concern there).
What epoxy/resin and rubbing/polishing compound would you all recommend to fill in a deep scratch (couple mm's) and then smooth it out? Appearance is the only issue.
Thanks!