I've had nothing but problems with mine, and I can't wait to get rid of it.
I honestly thought I would like it; there's so much to like:
small, so therefore easy to park
quick enough to get up to freeway speed whenever is needed
nimble steering and cornering
fuel economy is supposed to be good
hatchback for plenty of cargo room
interior is laid out well, but simple
Stereo has an aux-input! Woo!
Not bad looks (for the newer gen, I have an 09)
However, I soon found:
RATTLES. Tons and tons of interior squeaks and rattles
The front suspension feels as if it is about to fall off the car--FOR THE SECOND TIME. Car only has 21k miles on it!
Actual fuel mileage isn't what they'd lead you to believe (automatic) Any speeds above 65mph = 21mpg (freeway, anyone?)
Constant OnStar issues, and for some reason they throw a check engine light? Really? For an optional PHONE?!?
This is minor - but the stock tires only lasted 11k miles? Really? The tires on an M3 last that long.
My warranty expires this spring, and I've already ordered my new car so I have it before the warranty is gone.
I tried and tried to like this car, I really did.