Places to list your X for sale:

Ebay - Great exposure, you can post multiple pictures
Cars.Com - A lot of other X's on this site, you listing might get lost in the
shuffle
AutoTrader.Com - I like it better than Cars.com, not a bad place to sell

Oh, go to a nice place... a park... by the water... and take really nice pictures! I was amazed in my recent search for an X5 how bad some of the picutures were! A good location will make your truck seem all that much more impressive!

Be honest in your ad. Point out ant problems scratches or issues. The buyers will know you are an honest person and want to buy from you.

Good Luck!!