Yah, I did it once.
All in all, it worked OK.
You just put a description of the vehicle, include the VIN, and a picture or two.
Be explicid in your description of the product, and talk it up, but don't lie.
Be sure to set down explicidly what you expect from they buyer and what the buyer will expect from you, then live up to it.
Read the fine print in the agreement and the costs of doing buisness on EBay because they are the rules you will need to work with. If I remember right the costs of the ad slide with the selling price and and can be large, be sure you cover that with your selling price. EBay uses PayPal, infact IIRC EBay owns PayPal. You will want to set up an account that will allow you to receive payments and move them to your personal account.
If you plan on going the auction route, to protect yourself, set a fixed amount you will not sell below. If someone wants to go around the auction process, they do not recomend you deal with them because then the umbrella of protection for the seller and buyer enjoys disappears. Also, do not give out the minimum price. A few times I have come out much better from refusing these offers of "kindness"
What I did was set a minimum price I would not sell for, and also stipulated an amount down X number of hours after the auction with the balance being COD. That way they buyer was motivated to pick up the merchandise. If the buyer failed to honor the contract after the sale, and you file a grievance, and they find it valid, EBay then will allow you to repost at no charge.