Do you ever plan on modding and drag racing? The M6 flat out sucks for drag racing due it's really crappy 1st gear. They are also harder on an already weak rear end and have weak syncros. If you plan on just driving the car and leaving it stock the 6 speed is fine. Personally I would put a 3500+ rpm stall in your auto and have a blast. BTW my car used to be an M6, I changed it over for the reasons above.

 

The older you get, the more you enjoy an automatic.

 

never planned on turning into a (race car). i go to the track once a year. i was doing cat back and intake on the m6. thought maybe header sometime pcmforless tuning. thats about it nothing to radical.