I've had my Passion since August, and it's been fine. I have about 6500 miles on it now, with no problems other than the interior motion alarm sensor's being faulty. That will be addressed at the 10,000 check up.
Cold weather has brought out some issues, one good- two bad.
The seat heaters work great; in fact my side quickly gets too hot, so I switch to position 2 after a few minutes. (My wife's Infiniti M35 takes forever to heat up.)
The ride has become much more lively and hard now that temps are at freezing or below. I guess the shocks are less efficient at cold temperatures.
That silly hook that holds the rear cargo cover up is almost impossible to secure in the cold. I've had to sit with my knee against it to lock it,and getting it free again is even harder. Who thought up that design?!?
Overall, the first 6000 have been great. There are only a few Smarts around Princeton, so mine still gets constant smiles and comments from other drivers. My mileage has fluctuated slightly between 38 and 42 MPG in combined city/highway driving, even now that the weather has turned colder. That's fine with me. I have yet to take it on a long drive of constant speed, but I would expect to reach the mid 40's on such a drive.
As gas prices begin to climb again, (Is there anyone who doesn't know that will happen soon?) the car will make even more sense than it does now. Until then, I'm certainly saving money by not running up expensive miles on my 2001 Pathfinder (16 mpg), a car that I would never buy again. But since I already own it, it works fine for hauling my dogs around and towing my boat.
Best regards,
Irv