I previously owned a 02 6cyl mustang and bought an 02 8 cyl mustang with the 5-speed transmission about a year after selling my 6 cyl. I got it when it had around 100,000 miles and have performed only routine maintenance in 10,000 miles. I was told it had the clutch replaced right before I bought it. I would recommend getting the 8cyl if you have the opportunity as it has been much more fun to drive. The trim was better shape than I would have expected for 100,000 miles. No leaks or rattles however my steering wheel and gear shifter were badly worn. I'm not sure if this was from the previous owner or if this is common. Mach 460 Stereo has great sound. Driver's seat is also comfortable.
Great fun to drive and I liked the looks. It had aftermarket Flowmaster exhausts when I bought it, which I didn't originally like but would now highly recommend. The sound really adds to the experience of driving the car. Premium version was well optioned with leather and nice wheels.
The only issue I have with the car is the transmission. I changed the fluid but it is hard to shift into every gear except 5th and sometimes will momentarily not go into a gear. I wasn't really expecting perfect from a 100,000 mile car and this hasn't caused me any big problems.