You can do that now, at least individually after you reach the garage. click on the => arrow down at the lower right next to the add or boot buttons. This allows you to add individual cars of your choosing.@Marcel Offermans I hope the opponent selection allows you to select the AI to race i.e selecting any GT3 cars does not pull across every skin for that car rather it allows you to select the AI cars you want to race against namely ex all the World's Fastest Driver skins?
I would rather it works inversely tooYou can do that now, at least individually after you reach the garage. click on the => arrow down at the lower right next to the add or boot buttons. This allows you to add individual cars of your choosing.