I have done 2 vehicles like this, 1st...represent the vehicle honestly, and list any major issues or work it needs to prevent a dispute in the future, 2nd...put in a reserve!
Decide what is your least you'll take for it, and it will show on the bidding to the bidders.
If you don't get a bid high enough, and you have some active bidding going on, you will probably recieve an email asking what your minimum is and they will make an offer accordingly, so keep that in mind.
Ebay will also have a sale on listings, but I'm not sure if that includes vehicles or not?