Transmission went out at 90,000 miles (2001). However, it was due to my ignorance of the car's design. Unlike most other cars, this model Prizm has a differential reservoir that fills from the underside only, separate from the transmission reservoir itself. The seal around my Constant Velocity shafts, where they enter the differential, was leaking. I regularly checked my transmission fluid levels (from above), seemed fine, thought nothing of it. Apparently, the differential drained dry, so my transmission seized up on the highway. I hadn't noticed because the clicking sound that preceded it for a couple weeks sounded like Constant Velocity shafts going bad, so I replaced them (as the boots on those were broken). Fortunately, a friendly fellow from Detroit stopped within minutes and we returned home safely.
Constant Velocity Shafts replaced at 90,000 (2001).
Muffler replaced at 110,000, in 2002.
Starter went bad at 120,000, in 2004.
Water pump at 120,000, in 2004, which dripped onto my timing belt and ruined it.
All the above were original manufacturer parts, which is pretty amazing when you think about it, especially the muffler. Was able to perform most all work myself, except the water pump. Unfortunately, the engine must be removed to do this.
Never had a problem finding after-market parts at major auto parts stores.
All in all, it sounds worse than it was. Being already 10 years old when I bought it, it had been passed around and some maintainance neglected, but I only paid $2000 for it, so I feel I got my money's worth in four years of everyday use.