I saw one at a car show in downtown West Palm about 6 weeks ago, and then I saw another one at Moroso last week. I know the person that owns the one I saw last week, so it was not the same car twice. If we add Mark Starrs to the equation, that makes up for almost half of them.
Lotus Cars US imported 8 (complete with x of 8 engraved plaques between the seats). Two of them ended up here in the Seattle area and were sold by Park Place, Ltd. (Although, I think the owner's family bought both of them). Those 8 are NOT street legal (although they do seem to see the streets wearing dealer plates once in a while)
At least one additional 340R, owned by a european national and brought into the US as his personal car when he moved here was resold through Park Place last summer. Apparently, it is street legal through a grandfather clause in the foreign national car import laws.
So, out of the 9 340Rs I know of in the US, one third of them are in the Eastside metro Seattle area...
I brought mine in to the USA last year and I know of another being taken over but both were subject to US Customs laws.
These mean that no changes were required for fedreal compliance and these could be driven on the road with UK plates
however we had to
1) not sell them
2) take them out of the country within 12 months.
It might be possible to get round these laws by driving into Canada and selling it there. But there's probably some Canadian Customs and Duty laws that'll need looking into.