Thanks to all.
I have found that the tax and duty is nill, provided that I can prove that I have owned the car for 6 months prior to import and keep the car at least 12 months after import...
This seems really good for me...
My car will only be used on week-ends and mostly on the track anyway so it's better to have a LHD car for me. Next thing is that cars cost 2/3 in the US of what they cost in the UK. With the $ where it is and resale value where they are in the US, I couldn't even buy a Boxster in the UK (OK so you get my point
)
JM