Nothing lets me down more when I drive an hour to see a car I am interested in buying and the owner could not bother to make it presentable...especially when its advertised as 'clean.' Not a good way to start the sales process.
Here are two great reasons to clean your car before selling it:
1. We judge a book by its cover - Let's be honest, first impressions are everything! If you are trying to sell or buy a car that is filthy it's going to make you question how well the car was cared for. You might have taken fantastic care of your car mechanically but its easy to question when the cup holders are filled with brown goo.
2. Spend a little now and get more later - people love to haggle and get a deal. Don't give them more bargaining power. If your car is clean both on the inside and outside that is less ammo for a potential buyer to negotiate on. There is no question if your car is in good shape in terms of appearance and mechanically you will get more money.
Here is an example of a car I prepped for sale, its amazing what the difference can be.