[ManhattanBMW]

I have driven both an M4 and M6 at speed on the autobahn (170 mph for the M4 and 190 mph for the M6) -- the autobahn is certainly not just a straight road --and from my experience, I would rate the M6 as the superior vehicle. In particular, the M6 was more stable at high speeds, and from 120 mph onward, it still pulled strongly, whereas the M4 just does not continue to accelerate at the same pace once at high speeds. I also find the M6 interior to be a more inviting and comfortable environment for sustained high speed travel. Do not get me wrong, the M3/4 is a great car, but on the autobahn, I would rather be in an M6, and frankly, it probably offers a better experience than being in most exotics.