get on a us car site (craigslist? greggslist? creggslist???) and see how much a US zed is, as others have said, i'd sell yours here then buy a LHD one in the states, trick it out with some pimp US goodies. Plus if you buy a Californian one it probably wont have seen any salt or rust.
If you dont want to sell here, is there anyone here you trust with a long term loan of a zed? a famiy member could look after it for a while for you, either drive it or SORN it and store it, with the usual provisos about long term storage of cars.