You've got a couple of options here. If you choose to sell privately, you'll generally get the best return and have fewer outgoing as many websites don't charge to list your car for sale. The negatives are it will require more of your time, both dealing with inquiries and putting the adverts together. If you choose to sell at auction, much of the hassle is removed but you'll have higher fees to pay. So the best way to sell your car depends on how much of your time you can spare.