I hope most of you are aware of BMW's Secret Underground Garage where they store all sorts of awesome cars. However, if you're not aware I would suggest finding and having an additional pair of clean underwear at the ready.
To start things off we've got an E30 pickup/ute
Followed by an E34 M5 convertible
My personal favorite the E36/5 ///M Compact
Another beauty, the E36 M3 GTR
The E46 M3 Touring
Finishing up with the Ur-Roadster, or a Z1 M essentially
Theres a few more here along with a full writeup