smart fortwo earns IIHS’ “strongest roof” rating among all cars in its class, also outranking other larger cars in same test BLOOMFIELD HILLS, Mich.--(BUSINESS WIRE)--The 2009 smart fortwo today was designated “strongest roof” among competing micro and mini cars by the Insurance Institute for Highway Safety IIHS), confirming once again that the smallest car on the road is safe. The IIHS tested roof strength, and the smart fortwo was the only vehicle to achieve the highest rating of “Good” in its class. The smart fortwo also tested higher than all but one of the 13 small SUVs previously tested by IIHS. Roof strength is the most important vehicle attribute for protecting occupants in a rollover crash according to IIHS.