Ever the nay sayer I will be. Although the hype is that the Ford Fusion is so great, I have a good friend who has not had great luck with her 2007. At 22,000 miles she is on her second set of brakes all the way around, the tires went at 19,000, The engine is noisy and under powered (4 cylinder). The mileage is OK, but about the same as my AWD Subaru Forester. I don't think that seems right.
Overall, I would approach a high mileage Fusion very carefully.