How can I trade this car in?

Very first thing I would have done was to get the financing out of his name and in to your own. Most likely the payment would have been lower as he had been paying some of it down. 2nd, you need to talk to him about trading it in. If I remember correctly in order for the dealer to purchase the car for a trade in, they need to have the registered owner present. You will need to check your local laws on that one. now when it comes to talking with the brother, if it where me, I would tell him, "Hey thanks for the car, it's been really nice to have, however, I'm finding I need something a little larger/smaller/ more fuel saving, etc. something that doesn't say, Hey this is a lousy car. Even saying, something like more safety features is always a big win. I hope this helps.