As has been said before: More pictures (lots more), raise your deposit to 10% (nonrefundable and due within three days of auction end), and make it a PRIVATE auction. The problem with having the bidder identities "public" is twofold: First, some bidders prefer to remain anonymous - especially dealers bidding on the car. Second is that you open all of those bidders up to scams galore. Nigerians (and others) will contact all of your bidders and offer the car for a cheaper Buy It Now price while faking your identity. Some will even set up a quick - and fraudulent - auction to do so. And they will use your pictures too. Others will offer everybody on your bidder list a Second Chance offer for a ridiculous price (something like $35K) with an immediate deposit of $2000. They then take the deposit and run. Make the auction private and you avoid most of that (they can still set up a fake auction but not contact any of your bidders). You will also get more bids.
The other key is to provide a FULL description, especially disclosing any faults the car has. While it is painful to document every scratch and chip (including pictures), it demonstrates that you aren't hiding anything and are providing full disclosure. Most people won't drop $50K on a paragraph and five pictures. Nothing personal.
This one is a little wordy (okay, a lot), but got a good price for an '03 with this many miles - and tracked to boot:
eBay Motors: Dodge : Viper (item 140023451313 end time Aug-30-06 15:19:08 PDT)
Hope this helps, and good luck!