How much equity is in the jag?
If money + loss isn't a issue, anything canbe negotiated!
I would consider trading for a used Z4 instead of a new lease.
possible, I know that http://vuthang.net does that.. but I'm not sure of the specific model
It's true, I have seen 2009 BMW Z4 with included body kit there. I am not sure if they allow swapping or something like that. If you want another choice, yahoo auto also provide more information.