Having the same issue. Pushing BMW to send me the correct bolts once they admit to the issue. I don't have access to a grinder so have to hold off until I hear back from them! The bolt cage on the bumper carrier was made for a 16mm head and the bumper carrier bolts in the kit are 17mm heads!

Seems like a lot of work to get them to fit. Grinding each one of the 4 on every side of the bolt head to keep it centered to fit! How long did it take you and what kind of grinder did you use?

Also, are there any concerns about the strength of the bolt after all the grinding?

Germans being all about precision, I am disappointed that the BMW factory kit had such an elementary issue!!!