Okay so basically I was doing the bike glitch and I clicked sell bike sold it pressed start went over to xbox games store and I then pressed a once before I lagged out and it took me to single player. I then went back on to a invite only session and went to the mod shop with my Bugatti and it gave me the option to sell my Bugatti for 150k as the sell option was still there that normally appears when you drive in on the bike.... Not sure if there has already been a way found to sell cars bought of the Internet but this could be a way.