| NB,
From a friend who tried to bring a Smart Car into the US from Canada before they were allowed to be sold here ... first of all, there's no need to convert RHD to LHD for registration reasons. It's just the ease of driving. But RHD vehicles are street legal.
Second, bumpers are apparently the big thing ... she had to convert from Canadian to US bumpers. And rear wheel arches needed to be refit with reflectors. Then she had to do something or other to prove that it could go at highway speeds ... she couldn't explain all that well to me ... apparently they wanted to register her Smart car as a farm vehicle (i.e. non-Interstate driving). The One isn't sold in the US, so make sure whatever the regulations are on interstate cars, that it will pass US requirements. | 
