I'm just about to pull the trigger on an M3P, and am trying to understand as much about it as I can before placing the order... I do a 400-mile each way road trip several times a year. There are superchargers along the way, and the trip planner suggests that I stop at one that's about 125 miles into the trip, then another that's about 150 miles further. Given the car's rated 310-mile range, this makes me think that 275 miles of highway driving isn't feasible. Can anyone tell me the car's realistic range at 80 mph with the AC running? Sales dude ("Owner Advisor") suggested 260 miles, but I'm not sure that I believe that... TIA for the input!