I voted for the Mustang, but just because it's the least expensive. I have to admit I want one, but I don't know if I'll ever buy a new car.
Sorry - this is a fun question, but I'm going to get serious here.
Not to be a downer, but I don't really understand why people buy brand new cars. If you are rich - your house is paid for, you have your retirement taken care of, your kids' college, etc, etc. - ok buy whatever you can pay cash for. No problem at all. But don't take out a loan for a car. It's a really bad financial move. You should seriously question whether you want to stay with a woman who spends money this way. You don't want to be stuck living paycheck to paycheck your whole life.
Why buy new? It's just throwing money away. Especially for a mechanically apt person who enjoys fixing cars. Do the math and figure out how much money you will save over a lifetime of picking a less expensive option. If you pay the extra money on your home loan every month you could save years and 100s of thousands of dollars on a mortgage. Your savings could easily be over a million dollars, as you will have more money to invest in retirement as well.
I drive junkers, and I love the feeling of knowing that I paid about one monthly car payment for my current driver. I'm also having a blast driving it. Anyway - good luck with the decision - any new car should be fun for her.