New G8 GT

No. What he paid is exactly what you were asking. A trade in has no bearing on what he paid, a trade in is essentially them buying the car from him and he buys the G8 off of them. Say the car cost $25k but they gave him 10k for the trade, even though he only has to pay out of pocket 15k for the G8, the car still cost 25k no matter how you shake a stick at it.