2005 Pontiac Gran Prix GTP(testing waters)

Testing waters on this. it has around 47k on the car has an intake and afteramrket boost gauge. I wanna get a better fuel economy car for my daily highway driving to and from work. KBB on it is 10,830. im hoping to get at least 9 for it.

how does it work if i trade it in and its worth more then the car im buying?

They’ll give you the difference iirc.
But you’ll get stiffed on the trade in no matter what, so meh.
and you don’t have to pay tax on the car either I think.
Since you already paid tax on the car that you’re trading in… unless the total cost of the new car is more.