Strange but true...
I've driven about a half dozen 1ers. Mostly 120ds, and a few 118ds. Had a ride in a 118i that had done a good few laps of the 'ring. All had the same problem.
Crazy thing about these cars is that they understeer like and Audi or VW! They wear out the outside of the left fron tyre in no time. The 3er doesn't seem to have this problem. Could it be that they are a bit nose heavy? Set up for really poor drivers? What gives?
"Simplicate and add lightness"
Your friend at the Nordschleife.