That looks like a nice car, but never, never, never say that you want to by a car on the same site that said car is listed prior to negotiating a price
It limits your ability to then negotiate as the seller knows that you really want the car
When you take it for a test drive, make sure that the seller takes you on a long test drive. A couple of miles around the block is not enough. I spent about 30 minutes in the car when I purchased mine and when I sold it I spent on and off about 3 hours in the car with the buyer. Some things do not show up during the initial startup and drive. Make sure that the car is brought up to temperature, let sit for a few minutes and then started up again. Good luck.