So, Newton's laws of physics are wrong then? I'm not arguing that it, the Smart, is safe in a crash against itself or something of equal mass but it just isn't so when you consider it against a larger mass. That roll cage or "egg" as it is referred to can only absorb enough impact shock that the units materials can handle. Breech that point and the elastic limit is done and doesn't come back.
To think that an E class isn't the same is also foolish. 1, you can't go 200 MPH in a smart car and 2 3 or 4 people can't fit in the smart car. For a Caddy (K1500) to travel that fast it would need very little modification but it would only be able to do so in a straight line since America cars and trucks aren't know for being agile.
NHTSA ratings are much like JDP, follow the money and you'll figure it out.
I found this online:
Amazingly enough, when the Insurance Institute for Highway Safety (IIHS) tested the Smart ForTwo, it did receive their highest rating for side and front impacts. However, it fell short on whiplash protection, one of the most common injuries. Smart USA was looking for a Top Safety Pick designation to assuage all fears and concerns over its petite frame but the IIHS nipped that in the bud when spokseman Russ Rader made it clear that even though there is not a specific size requirement, the ForTwo is "just too small to be considered safe under all driving conditions". In fact, the ForTwo is the smallest car ever tested by the IIHS and is classified as a "microcar" due to the minimal crush space on the front end.
The National Highway Traffic Safety Administration (NHTSA) conducted their own tests which also illustrated some room for improvement. 'Five Stars', the top rating, was awarded for driver protection in the front crash test but passenger protection was given only 'Three Stars', a pretty low rating that most vehicles never see.
Both the NHTSA and the IIHS did give the Smart ForTwo top ratings for side impact collissions. However, both times the doors became unlatched during the test. While not ideal, it didn't actually affect the test results.