Anybody out there have experience upgrading at the dealership? I have a leased X5 and I'm thinking about changing it to a 7 series. I have to turn in my 5 series at some point this month and we'll be without a sedan. (only the SUV and mini-van are left). I've done this in the past with lower end cars and always ended up eating a big chunk of change. I'm hoping somebody has some advice or maybe a web site that points out how to go about this and get the best deal. Being that the we don't have an urgent need to trade it in, I figure I have a bit of negotiating power and flexibility with timing.