Reading loads of reviews and feedback about car transport when trying to pick a company, I concluded it's a crap shoot. It seems no company has *all* positive reviews. You just have lower risk/higher cost with the 'prestige' type names who own their own trucks and specialize in high end enclosed transport.
I went with Passport Transport, to take my M2 from NJ to Los Angeles. We then flew out to meet it and drove it around the West and back to NJ, ~5k miles. Good experience with the transport (fantastic experience driving the car on various exciting coastal and mountain roads out West
). They gave a pretty wide window of time to pick it up and the transport time. That seems unavoidable, though not ideal particularly in my unusual situation of wanting to plan a trip around flying to meet the car. But they picked it up around the middle of the pick up window, and the time out to CA once they picked it up was also around in the middle of their estimate. The driver Mark, their drivers are company employees driving company trucks, clearly knew what he was doing and loved cars. I got a good feeling from that right away. And the car was in perfect condition when I picked it up. A little pricey compared to some, but worked out for us. I'd go with them again.