The M6 GC will give you the impression it's a much larger and wider car.
The M6 GC is NOT on a 7-series frame. The 7-series frames are on a 126 inch or so wheelbase, so it's not even close. In fact, the M6 GC and M5 have the EXACT same wheelbase length. EXACT meaning, literally down the same fractions of an inch.
What the M6 GC and M5 does deviate from a measurement standpoint are:
1. M6 GC body length is about 4 inches longer (all of which attributed to the front bumper design), and ONLY 0.5 inch wider on the body.
2. M6 GC body height is 4 inches shorter than the M5
3. M6 GC track and body width are 0.1 and 0.5 inches (respectively) wider than the M5
4. M5 passenger compartment is 2 inches wider than the M6 GC (M5 can legitimately seat someone in the rear center bench.)
5. M5 rear passenger headroom is marginally higher than the M6 GC (the rear is 1 inch taller in the M5, front headroom are the same)
6. M5 weighs about 10 lbs lighter than the M6 GC
7. Finally, if you're talking about the M6 coupe, it's a smaller car. The wheelbase is 4 inches shorter than the M5/6GC and slightly shorter in height.
http://www.bmwpower.ge/pages/technic.../f10-m5-sedan/
