A bit delayed, but:
While ball cups are obviously up for debate, the small RPM front bumper for the B4 should be an AE stock part.. it's beefy as hell and has saved my bacon dozens of times. Offers way better protection, lasts way longer, it's more secure, and it's five bucks. Absolutely recommend it for anybody, even if you're good. Too bad they don't make a motor guard..
I use it. It's on mine in the pics above.