The 700 is the big block motor, and they are known to have vibration problems. The 600 is the HO motor and it very good. So just keep that in mind. There is a TON of information on the Fusions out there. They stopped making them for a reason.... Although I 100% agree the ride is very good. Just the motor issues (900's for the most part) caused the name to be a bad thing. The Fusion was the first "IQ" set up. I had the 06 600HO myself, and loved it. If it needs a new track, you are looking at $500 or $600. At that milage, I'm sure it needs a lot of maintenance if the guy hasn't done any. Shocks, checking the suspension, etc. I don't think $3k is a "great" deal. If you can get it for $2500 or less, that would be maybe worth it.... in my opinion.