Wobie doesn't throw up as much when he is inside his carrier, and can't see out the window. I also keep the air conditioner on pretty high. I also take him on a long run right before putting him in the carrier, so he hopefully sleeps through the ride. I get carsick really easily too, so I can sympathize with him.
He takes car rides several times a week, at least, and he gets carsick about once or twice a week.