If you have an Aveo, GM recommends replacing your timing belt at 60,000 mi; however, mine broke at 55,000 mi (mine is a 2004). Apparently this is a huge problem with the Aveo and Wave. The parts are cheap even for a belt (they use a plastic idler pulley instead of metal like most cars). No one had even mentioned this to me, so I'm a bit miffed at the $2,000 fee to fix my car (all 16 valves broke, the timing belt has to be replaced, as well as the idler pulley and other things that were damaged during the break). Replace early and often, I guess.