Not many. Just caught the bug during residency when I got to drive a friend's e90 328 in 2012. But better late than never!
2011 E90 328i stock (god, I miss that steering, and feel of the cockpit). I don't miss taking care of the Jet Black paint though!
2015 F31 tuned with AA piggyback. After the tune, maybe the best, simplest DD I ever had. Was perfect. Even had the leather dash.
2015 F30 335 tuned with AA piggyback, AA muffler and res delete. My family called it "Loud Car"
2018 F80 ZCP tuned with JB4, DPs, and chargepipes. Absolute blast. Would have been happy to get into the G80, but they ruined the design, so F90 it is