Probably the same ad agency that developed the commercial with the idiot salesperson who crank calls his old dealer. The marketing MBA in me cannot see how that would inspire any consumer to want to buy a Chevrolet (”buy from us, our salespeople have the maturity of a five year old!”). Then again, it is a typical GM corporate mentality concerning reaching their customers, as well as their overreaching self-absorption and arrogance.
For the size of GM, $600,000 is not a big contract, especially if the ad agency is quite large. It’s entirely reasonable that he didn’t know and if his wife works in a different office, she probably didn’t know.