The X6 has low residuals due to the fact it is a niche/ status vehicle (that is how BMW sees it and the rest of the market as well) They will be hard to sell in a few years b/c no that many are looking for a large 4 seater. The other factor is the fuel situation.
Even though the depreciation is bad with the lease at least you are hedged against the true market. In the end you know what it is going to cost you and the rest of the money you would have used to finance you can put in a mattress or something!If the market is higher when the lease is up, sell it outright and make some money back, if it is lower you already made out. If it is the same buy it if you wish or move on. I always believe buying is stupid b/c a car is a depreciating asset and in the end you never really "make" money and in these times it makes more sense to save that extra money you would have spent on the car rather than leasing it. Let BMW take the hit, which it will some SUVs have been taking a 50% hit in the first year, I was talking to a wholesaler yesterday and he was amazed what he can buy today, the closet vehicle is the RRsport and he said it is at most 50% right now, so the X6 is not far behind.
Best of luck!
2008 ///M3 Sedan. Jerez Black, Black Novillo/Sycamore, ZTP, ZPP, ZCW, iPod, Enhanced Premium Sound, 6 spd.
2008 328Xi ED 9/25/08 (Hers) White, Beige, ZCW, Xenon, Step.
2007 530XIT ED 3/22/07. Mystic Blue, Auburn, 6 spd Manual, ZPP, ZSP, ZCW, Nav, PDC.
2006 325i ED 8/29/05: Retired