Any opinion on getting a G35 coupe?

So I'm starting to get tired of the 01 Focus and its automatic transmission and I'm thinking of using it as a trade in on something better.

I really want the following things:
-RWD
-6 speed transmission
-2 door
-Corners well
-under $15k
-under 90,000m
-rear seats

I was thinking along the lines of Mustang/Camaro, but the ones in my price range are either V6s, automatic, high mileage or made in 2000. The live rear axles don't appeal to me either.

I have 2 months left on my insurance, so will possibly wait until that's near renewal to replace the focus. It has 38,000 miles on it, which is pretty good, it just isn't very appealing to me to drive.

I might go to the dealer to see if I can test the car and how much they'd value the focus at, just wondering if anyone has any experience of infinitis or could suggest a different car with my wants (I really want to avoid BMW though). I only noticed the Infiniti because I saw the 6 speed transmission and then a V6 motor, which I can live with...