I just bought a 07 Mazda 6 from a private party with 125k miles on it. For the most part, it's in clean condition...the only thing I noticed is that the ac doesn't work. Since I have been driving it though, it starts shaking when I brake and the engine seems to take a little time to turn over when starting it. It's almost like it chugs a little before it starts. Any ideas what these problems could be? Carfax had a clean report and it has been maintained. How long should it last me? Thanks!

 

Love this Video, even though they don't know how to spell brake (break): Video: How to Diagnose a Brake Problem | eHow

Think you need new rotors and pads (#8).
Engine wise: spark and fuel. Car has very Hi mileage! means it's time for new spark plugs, ignition coils and possibly leaking fuel injector seals. Chugging could also be oil leaking in to cylinders from valve seals. The car is old and a compression test may be in order. Watch the oil consumption.

 

Long wind over time can be a sign of a dying fuel pump.