I would definitely try to negotiate the payoff if you decide to keep as the value of used cars is a bit lower these days than in 2008 when you purchased, so the residual was a bit high back then. You can buy a loaded 2008 X5 certified with low miles off the lot for 40-42k pretty much anywhere, so if it is 2500 to CPO, you should be looking at maybe 38k for the buyout, otherwise you better off letting it go!