I bought an Ion 2 just over a year ago, I've got 20333 miles on it, and I haven't needed a thing done to it.
The transmission does shift funny, a new "Power Braking" aspect where it will downshift on its own to hold a speed going down a hill. This is actually not a bad feature, but it has some bugs to be worked out. It also doesn't up shift sometimes when it should.
Bottom line, I would buy another one in a heartbeat, I just wish I had waited a year for the Red Line edition.
I own a 2003 Saturn Ion Quad Coupe Series 2. I bought it in May of 2003 (have 16000 miles on it now) and already have had the valve body replaced on it, and there is a problem with the transmission that makes some grinding noise at about 10 mph. The alloy wheels are junk, I drove on a gravel road and they got all chipped up, luckily the dealership replaced them, but still knowing that I payed extra for them, they should at least be a good quality. I have actually called and spoke to someone at Saturn (not just the dealership) and they said that the Saturn engineers are working on it. Since the VTI transmission was first used on this model of car there are still some bugs to be worked out. Overall I really enjoy the car, I get a lot of looks and compliments on it. It has some get-up-and-go to it, though the automatic downshifting is something to get used to. The seats do stain easily, and even though they have dent resistant panels doesn't mean they don't scratch. In fact, it scratches really easy so I need to see about getting them buffed out. I do like my car and I want to keep it for a long time.