Most cars, (and Fords in particular) will go through a big maintenance cylce at 90-100K miles or so. Expensive things like the AC compressor and ATX will be replaced, and neither of these are cheap to fix. This is the main reason why our cars have such poor resale value.
I usually buy most of my cars at this point and have a relatively good next 100K. The 2000 SVT I just bought has already had the engine, tranny, clutch and AC rebuilt. The way I see it, it should be good to go for a few years.
