One piece of advice if you're getting a 3 (or any car) with a moonroof....unless you're coming RIGHT BACK to the car, always close your roof when you park and leave it. A friend of mine left her moonroof open for about 5 hours on a sunny, windy day and her tracks got blown full of sand and grit....now her moonroof makes grinding, gritty noises when she opens and closes it. The sand and stuff blowing around in the wind got stuck in the grease in her tracks, and Acura wants $300 + to disassemble and clean her moonroof. Cleaning the exposed tracks is easy enough to do yourself, but the dirt got all the way back inside her roof - into places you can't get to unless you take the headliner and other parts out. Not good..... As far as leaks go, a moonroof won't leak inside the car unless your drain holes inside the gutter are plugged up, which is rare. An aftermarket sunroof can leak, as they don't have a gutter system. If you like the open roof experience, fear not, as long as you take steps to prevent problems like I mentioned above.