I have been in sales my whole life. All you need to do is this...
Call her your silver medal, then demand she make you dinner, and then hit the bar with your friends. When she asks why you're being such a dick, tell her it's either the 4Runner or a divorce, and go back out with your friends. Punishment works sometimes.
If she decides the 4Runner, you're golden. If she decides the divorce, then just make sure you hire a lawyer that can get you the 4runner in the settlement.
Seriously though, you will have to draw it out over a couple days, but talk to her about one of your "Friends" who owned an Acura and had all sorts of issues with it, but play along and tell her you want to "Do some research" on the car. Play into her, agree with her, play into the scenario. When she sees that you are considering it and taking it seriously, address your concerns with Acura's warranty, the dealerships ratings being bad, whatever. Find some horror stories on the internet about Acura's, and just say, "Honey, read this," when she is around. At that point, you have bought yourself a couple days to find a selling reason to keep the 4Runner (Towing needs, trips to the hardware store, kids, pets, etc). Reinforce why you bought the 4Runner on the first place, and remind her that though it is tough on gas, the maintenance isn't, compared to an Acura, and the reliability of a toyota is Huge. Reference this article too:
Toyota 4Runner - In Photos: 10 Vehicles That Can Run For 250,000 Miles - Forbes