risks of buying a car that's been on a lot for 1.5 years?

I'm interested in a 2008 Ford Fusion that is at a Ford dealership about 1.5 hours away. They sent me the carproof dated 2015 and I did some searching on the internet and figured out its been there for over 18 months. The price has dropped from over 13k to 7.5k. I have emailed the sales person and he told me "all the vehicles on our lot are turn key and ready for new owners. All our used vehicles go through a safety and mechanical inspection and are started and ran every week here". This is my first car and I'm very wary of potential (especially if expensive) problems. Should I let this car go? Or should I go see it and what should I be checking for?