I'm considering a used BMW...am I nuts?

Completely accurate. It’s either in your blood or not.

However, if I were buying a German car and looking for “sportiness,” then I’d opt for the used Porsche (Carrera, Cayman, Macan, Cayenne, etc.). I’d look for a used Boxster or Carrera, since I love convertibles.

Google the Bimmer forums and BMW’s X-drive, it’s supposedly a maintenance and usage headache.