Bought a E46 M3 with 66k miles 6 weeks ago. All was well, but the clutch was a bit worn and I went in for a replacement. Also, I wanted to have the state of the BMW Subframe repair checked for a more economical add of the TMS subframe kit if reqiured. Upon investigation and transmission removal, the Indy Shop found a rusted, large bolt sticking top up from the floor board of the trunk. The bolt is just behind the rear seats about an inch or two from where the fold down seat backs split. So, far, no one knows what this bolt is or why it is there? I have no strange clunks, thunks, or any other known subframe or differential bushing noises associated with those issues. No handling issues So, my somewhat curious and desperate question is: What can this bolt for? Why would it be there?