If you can afford it, it is absurd to buy something that is 55k that is not exactly when you want when you CAN afford the extra ~7k. Why would anyone spend 55k for something that is not what they want?
All the additional reasons stated regarding price is nickel and diming a 55k purchase. If you can afford either car what in the hell are you doing spending 55k then worrying about another 5-10k. If you can afford it, it is meaningless as monthly payments, or you should just have the additional funds to put down.
As for the wife, I only use my wife as an excuse when I'm weaseling out of something. Putting anything on your wife is a cop out. Any wife, I should think, would want you to spend the 10k more to get exactly what you want, IF you truly could afford it.