[starbot]

This happened to me when I over-torqued my bolts. I was lucky and was able to use pliers to grab the threaded-side of the bolt to loosen it from there.

If I remember correctly, I slid under the car head-first, so I was looking at the opposite side of the exhaust tip (the part that faces the front of the car). If you shine a light, you should see the threaded bolt that some pliers can reach to.