So far I have not experienced any problems with my car. In fact all I have had to do was fill it with gas and drive. I do have some minor gripes, but they are to be expected from a car of this age and mileage.
1. Sometimes the sunroof acts goofy when I attempt to close it; it will get close to closing, then retract back to open. When this does happen, I just give it a few more minutes to make up its mind.
2. Power steering fluid sometimes overflows from the canister. I've had this checked, and was told that this is pretty common because of the design of the lid. I keep an eye on it, and have never had to refill it.
3. Sometimes I notice a very faint burning smell. I took it to a BMW specialist, who found a very small leak around the seal. He advised me not to worry about it, because the leak is very small. According to him "It would take about 6 months for a half of a quart to leak out." I haven't experienced any spills in the driveway, so I'm trusting his knowledge, all while saving up some 'future repair cash'.
This is my 6th car and 1st BMW/European vehicle. My 04 Maxima was stolen, so after my insurance paid the lein holder, I decided to use the leftover cash to buy something straight out instead of financing. While I have appreciated the strengths of my previous vehicles, nothing has put a smile on my face like my 323. I bought this vehicle from its original owner, who had always had it serviced by BMW, and they had the paperwork to prove it. Not to mention the original window sticker, all of the manuals, CDs, and keys. And I got it well below KBB and NADA estimates :)
It handles like a dream, and the gas mileage is great. I love that it is so well balanced, and driving this car for me is intuitive. I find myself just going for random drives all of the time.
Although this is a coupe and I am 6 feet tall, I have no complaints about space. Keep in mind that I don't have any children, and I'm usually in the car by myself with the occasional 1 or 2 passengers. I have been able to travel comfortably with 4 people in the vehicle for long trips.
The sport suspension may be a bit too stiff for some, but it's just right for me. Not too soft, not too firm, you can drive this thing on rough city streets and not pay for it with back spasms later. You're talking to guy that drove a 00 Mustang for four trouble free years. However it was not nearly as comfortable.
I must admit that I had apprehensions, because my 04 Maxima had a larger engine and about 100 more horses. Let me tell you, the power from the 2.5 is more than adequate, so don't let numbers fool you into thinking that the 3 won't move. If it's not quick enough, you can always upgrade parts or get an M3 ;)