I came from a E60 M5.. I would highly recommend NOT doing it. The 335 is a MUCH MUCH better car. Do a search on my E60 M5 thread. Ended up lemon lawing it just like many on the M5 board. Just not reliable, horrible gas guzzler (6 mpg around town and 140-160 mile cruising range on a tank) SMGIII is a disaster, and a lot of the motors were burning a quart of oil betwen 500-1000 miles. Not a good sign. Much happier with the 335i. BTW, the M5 feels like a pig even in sports mode and EDCII. You will also be a little dissapointed with the torque around town. You don't get much of a push until after 4500-5000rpm as opposed to the instant torque of the 335i.. (of course proceded and intercoolers make an incredible difference too!)