I went the other day looking to trade in an 04 X5 3.0 for a 911 c4s and was offered $15100.00. I think you may be better of returning the truck and buying another for less than your residual.

I got this info from Tarry at leasecompare for a basis on value.

2004 BMW X5 3.0i

Above Average: $22,291 - Mileage: 31,420
Average: $18,579 - Mileage: 60,755
Below Average: $14,867 - Mileage: 90,090

Total Sold: 61