Incredible demand has created a waiting list for buyers trying to get their hands on a Smart ForTwo in its first year of official U.S. sales. Strong fuel efficiency, easy urban maneuverability and a very positive image have all contributed to the sales success, but now that the NHTSA's first round of tests are out, the Smart's image may no longer be an asset.

The results show the ForTwo scores four of five stars for driver protection in a frontal impact, but only three stars for the passenger. Worse, the rating is based on a collision with a similarly-sized car - a near impossibility, statistically, on American roads. The results would almost certainly be much worse against a larger vehicle, reports CNN.

Not that three stars is particularly good, even against another Smart - the rating equates to a 21 to 35 percent chance of serious injury.

Side-impact ratings are a perfect five stars, however, despite the door popping open during the test. Getting thrown from the car is a dangerous proposition, but the ForTwo protects the occupants well up to that point.

Roll-over resistance scores a mere three stars again, likely thanks to its short, narrow wheelbase and high center of gravity. The three-star rating puts it in the company of SUVs and tall trucks and indicates a 21 percent likelihood of tipping in a crash - not exactly confidence inspiring.