No, the mounts didn't break as I used cable ties specifically for this reason. I use one at each wing and one at each light mount, and it holds the bumper on fine.
I clipped a barrier and the ties broke, releasing the bumper. There are a couple of cracks on the bumper, but nothing that can't easily be repaired.
I've been thinking of selling it for a while, as it's a lot of money to have invested in a hobby when I have a new mortgage to pay. It's advertised on SXOC and Driftworks, but not on here as yet.