What sedan should I buy?

I currently drive an 05 Sunfire coupe. Since I now drive a lot of people around and everyone always complains about the back seat, I have decided to replace it with something larger and roomier, with 4 doors. I also do a lot of highway driving now so I need something larger that is more comfortable on highways.

My only requirement is that it must be larger than an economy class car, it must have 4 doors, and it must be no older than about 5 years old. I would prefer 6 cylinders as I want something with a bit more speed than a 4 banger, while a V8 would drink too much gas. And obviously, it must be within my budget.

My budget is whatever I can get for my car, plus about $3000. I have absolutely no idea how much I could get for my car, Sunfires are cheap but on the other hand it only has about 21,000 kilometers and has not a single scratch on it, it looks and runs identical to the day I bought it.

I'm thinking of something like an 04+ Grand Prix, I've seen them for as low as $7000.

A nearby car lot had an 03 Jaguar X-Type which I could have afforded but I heard Jaguars are too expensive to repair and maintain. I don't want a car that costs $80 to have an oil change done.

Any suggestions?

hmm... Mitsu Lancer?

Toyota Camry

Toyota Matrix

Honda Accord

Chevrolet Impala (this sedan can sometimes fit 6 people with its front 'bench seat').

Japanese cars however are very reliable.

I think the Grand Prix is a good idea.

Maintenance on newer Jaguars isn't as bad as it used to be as they now use many common ford parts.