I doubt any of the electronic auto trannie could handle the torque and it could be the manual is lighter and being the car is about 200 lbs more then base vette they did not want the weight of the A6 plus the torque converter weight.

Besides who would want a car like this to just stick it in D and cruise ?

Also this kinda excludes the wazer from buying one to just cruise it around when it really needs to be hammered on.