Would you pay sales tax (in states that have it) on the autopilot upgrade? If not, that is some incentive to take a wait-and-see approach (because you would pay if it were rolled into the purchase price of the vehicle). Also, waiting to add the upgrade would slightly reduce yearly vehicle registration costs in states where they are based on the purchase price of the vehicle. And waiting may also reduce luxury taxes on the vehicle (due to reduced purchase price). I am not sure whether or not all of those savings make up for the additional cost of adding it later, but they would definitely reduce the penalty.