E46 M3s are prone on rear subframe rot/failure. Witnessed 3 "mint" ones in my mates all at the same time, all in for "rear subframe strengthening".

Only changed to something new as when i sat down and totted up costs, it was ever so slightly dearer to run and maintain my 12yr old E46 330d Touring than what it was for my 2015 Fiesta ST2. I am gonna trade it in for something bigger though.

And above all if i was gonna spend "spare" dosh on a performance car, it sure as hell wouldnt be on another wanky sierra cosbang. Defo would be an E39 M5 or an E55 AMG