At the beginning of the 2008 STCC season, two of the BMW's had sequential 6 speeds. Later in the season, they reverted to 5 speed manuals due to allowed lower minimum weight, and thus no 6 speed sequentials remains now.
Simbin at first included some 6 speeders, but now they followed the real series and ditched them. But before this patch, the 6 speed BMWs had some serious tire heating problem - no matter how careful you were the rear tires would burn up.
I like the 6 speed BMW's because you cant use them like the other sequential cars and the back doesnt snap round if u use the G25 shifter as a sequential stick. I would change it to h-pattern but my Race07 + GTRE + STCC runs really really slow in the controls menu.