Sorry bud, but I just don't know why anyone would press bend exhaust on any motor were HP was a concern. I can't belive you guys cut out the factory mandrel SS bends in favor of press/crimp bends.
I understand if you are on a budget and can't afford mandrel bends, but you own an M3. Why not spend a few extra bucks on pre-fab bends so your exhaust dosn't need to be re-done later when you want more power?
I appreciate you wanting to mod your car, but from a fabricator's view I'm not impressed given the caliber of car you did it to.