Bump for an Outstandingly nice X5.
This X5 is absolutely beautiful and I thought I was the only crazy obsessed person that kept their vehicles this clean.
Wow is all I can say from looking at the pictures and your extreme attention to detail.
Don't give up on selling it if the other vehicle is still what your looking for. I keep my vehicles as mint as you do and had a Vette for sale a few years back for about ~$5K over 'market value' and ended up having a guy fly in from Texas to Chicago and drive it back home. There are people out there that will pay a little extra for something this clean and well maintained.
Allot of people don't understand that the 'market value' cars that they will try and compare will be no where even close to the condition of your X5.
Truthfully, I'd keep it if I was you, but with that said, I know what it's like to want that 'something special' that comes along.... I have health issues myself and lost 3 very close friends (ages 49-53) in the past few years. You only live once, so do what you feel is right and enjoy life!
Your obviously someone who takes exceptional care of their things and I have no doubt you handle all of your affairs the same way.
Best of luck with the sale!!!