First off, I wouldn't get the BMW's because maintenence would be way too expensive.
I also wouldn't get the Neon or Focus because the have a lot of miles on them.
I don't even know what you were thinking when you considered a Jeep Liberty

. First off, that one has over 150,000 miles. Secondly, the two cars I used in my driving tests were a 2008 Honda Civic (for my first two, it was a piece of crap) and the Jeep Liberty (for my last four, it made the Civic seem like a Rolls Royce).
There are 1920's Russian tractors more refined than the 2006 Jeep Liberty. The road noise is unbearable, it sounds like you're doing 100mph in a normal car even though you're only going 35mph, on a smooth road no less. It has no power at all. My Lincoln could probably beat it, or at least come close to it, in a drag race. The transmission is jerky, not to mention it's a 4spd Auto, not what you want. There is no space up front, no where to rest your right knee when you're driving (that might just be someone I do, idk, but it's important to me), and I've heard Jeeps aren't the cheapest to insure and to do maintenence on. Although I'm not so sure about the maintenence part, since it probably shares parts with countless other Jeeps, Chryslers, and Dodges.
The really only leaves the '89 Mustang. It's definitely the one I'd have out of all of them, but it's a convertible and I just don't like the idea of buying an older convertible (but you could just try it it since you live close to it). Your biggest problem would be fuel economy, depending on how you drive, I'm guessing you'd get 18-25mpg with it. 25mpg is being generous. Parts would be relatively cheap and easy to find, and the 5.0 V8s are really reliable.
As for the Mitsubishi, I have no clue about it. If you're interested in it I'd say you'd have to either call/email them or find the car in person. Something about the ad doesn't seem right, there are no pics, it's listed with
extremely low miles and a very low price.