Been there.. doing that..
Last year I had to go through the same thing in moving to Germany. I like GN ERGY's suggestions the best. I had SO many people lined up to 'babysit' the Buick while I was gone. I'm looking at a few years stay as well.
I kicked around shipping the Buick over here... (had a hard time convincing Lufthansa that the Buick was less then 70lbs.
) Actually, I had a coincidence where I met a person who professionally shipped cars and such overseas while I was at a carshow. The gentleman said that it would cost approximately $800 - $1200, plus you have to concern yourself with inspections, modifications, taxes, etc. After hearing that, I thought to myself, do I REALLY want to put the Buick through that? Granted, you won't have to get it changed to right hand drive, but still some of the lights will be changed, perhaps emmisions, etc. Then after all that, you have to get it BACK to the US when you leave, which I understand is even worse! Also, looking at the big picture... Germany has TINY little streets with tiny little cars. A fire-breathing Buick may not do so well in those conditions. UK rains A LOT, just like here (Germany). To make a long story short, I'm glad I didn't bring the GN now. I would love to be able to cut loose on the autobahn, but most other times, it would be a chore.
Getting back to GN ERGYs idea. I looked at storage facility prices and such, and they were unreal. Plus, I had to think about security and then prepping the car for storage. There are several articles out about storing cars. Don't have any handy at the moment, but a lot of the things you need to do was annoying to me. So I finally broke down and found someone to 'babysit'. Granted, I was lucky. I asked my folks and they agreed to run it once a week or so, keep it covered and take care of it. So, I was a little lucky there. But, I think it was the best way for me.
I've learned a lot moving overseas... what an adventure. Please email me if you have any other questions.