It's taken some time indeed, but Polyphony Digital has finally introduced a way for players to be able to sell their own cars in Gran Turismo 7. Coming as part of the November update (Update 1.26), the Car Valuation Service system is allowing players to flog vehicles to get some extra credits, with the feature becoming available following the completion of Menu Book No. 39.
The exact specifics of the feature seem a bit unusual, but what we do know is that you can head to the Used Car Dealership to sell cars for a determined credit price, which will change and differ each day, and takes into account factors such as car condition, PP, any customisations you have made and more.
Otherwise, this update is bringing additions to World Circuits, more events on the World Map, the Michelin Raceway Road Atlanta track, four extra cars (BMW M2 Competition '18, Ford Sierra RS 500 Cosworth '87, Nissan Silvia K's Aero S14 '96, and the Gran Turismo Red Bull X2019 15th Anniversary), and more.
Check out the full Update 1.26 patch notes here.