Let's not overlook the fact that these commercials are designed to trigger emotional responses. It's not based on logic.
"Oh, what a great idea! I could get him a new Lexus and he'd be SO surprised! And when I tell the ladies at the club about it, they'll be simply green with envy!"
They don't want people to think about what it costs, or whether it will be the exact car he wants, or whether they can really afford it, or whether they even need one. All they want people to think about is that moment where she opens the door and shows him the car sitting there with a big red ribbon on top. And you can be sure every Lexus dealer in the country is prepared to make it happen. If some woman calls to ask how it could be pulled off, they will assure her they will take care of EVERYTHING. "That's right, ma'am, all we need to do is stop by your house at your convenience to get a couple of papers signed." They would absolutely be prepared to drive it to your house at 3 AM Christmas Eve and leave it in the driveway with the ribbon on it.