How does selling as is work?

Used car sales between individuals, not dealers, are always considered As-Is, unless there's an express warranty/guaranty stated or there's fraud involved. Just list the car for sale. You could add the As-Is statement in comments or in description.

Don't you just love CarGurus and their inability to post answers when given..... Makes me tired of coming here!

Make that fact clear in your ad. However, since the vehicle is only three years old there may be a portion of the factory warranty still available to the new owner. It will be up to them to find that out. Generally speaking when you buy a used vehicle from a private person it is assumed you are buying the vehicle as is. As the seller you are not required to guarentee anything. But check with your local Office of Consumer Affairs to be sure. Hope that helps! Jim