What I heard is that it was a protective measure for the smaller dealers. Since the bigger Hummer dealers can offer better pricing, they can get customers to fly or drive out of state to buy from them, right? So GM came up with the policy that if the dealer sells to someone outside of their local area, then the credit for that sale will not show up in next year's allocation of vehicles. So that way, although the big dealer gets the initial sale, they don't get an H2 to sell in it's place next year.
Also, it encourages people to go to their local dealer for service, boosting that dealer's revenue, and hopefully accessory sales as well. I'm willing to be that Hummer makes a mint off of selling accessories, and the dealer markups on them are astronomical. How else could the dealers afford to give you a price break on installing them, vs. just selling them to you to put on yourself? That's my conspiracy theory for today.
Corvette= "The ability to pass with class"