is there an advantage to paying cash for a vehicle

Both new and used car dealers provide financing and they rely on that for income. When you look for a car, never say you'll be paying cash. always indicate that you'd like to hear all their options for paying and financing, and that will get you the best price on any car. When the deal is done and you're finalizing, then insist on paying cash. They might try to undo the deal, saying the price was contingent on their financing package, but that won't be enough to lose you; just head for the door and they WILL stop you.

Very good answer Ed.