As is described on Korman's website, the ignition coil mounting system on the E30 M3 is prone to failure
caused by vibration induced fatigue.
The recommended solution is to drill out the factory stud which is spot welded onto the fender and replace
it with a nice strong bolt. Since I was waiting for parts for my engine rebuild I decided it might be a good
time to undertake this improvement.
The hardest part was drilling out the remainder of the factory stud after I had lopped most of it off with a cut-off
wheel. The spot weld is very tough to drill through. But once that was done the rest was easy. I mounted the coil
using an 8 mm bolt with a wide fender washer on the backside to prevent the bolt from starting to pull through
the fender. This mod may seem like a small detail but nothing would be worse than to have the coil pop loose at a track event
500 miles away from home 8^(