Working in DX11 with Callaway GT3, the players I created to test custom skins were not visible in the vehicle selection menu. The rcd file and folder is created normally. Three months ago I had no problems with MCL650. I haven't checked if it is DX11/DLC or build related. I don't think I am doing anything wrong since I am very used to doing this every three months when a we start a nee champ.
From the tuning menu. I fill the different fields: driver, number, team and description if i don't remember wrong.
It is strange. When I create a driver with a b c d in the different fields, the car properly appears. However, the one I sent to you and my teammate's one do not. I will check again but the name of the driver (which gives name to the folder that it is created) seems to be the variable that is affecting here. I'll do some tests to verify.
I have successfully made the two cars visible by renaming the driver name and folder. The problem seems to happen since I had already used those names with McLaren650S. Apparently once a name has been used it won't work again. Regardless you delete the first instance. It seems to get stored somewhere...
I have found similar problem with names. If I created a driver and it did not show up in the car list, I could not use that name again for the same car even if the folder and rcd file was deleted but I could use the same name for a completely different car mod. The only way I could get reasonably consistent results was to close RF2 completely and restart it and then do the next driver and do this for each drive even then it would it would occasionally not work. Also sometimes a driver would be working ok for weeks, a then it would stop showing up in the car list even though I had changed nothing in that car mod. I searched all writable files and could find nothing relating to driver name and car mod except the folder and rcd file created, perhaps I missed it but it must be saved somewhere. Hope the suggestion of closing and restarting of RF2 is helpful. It's a very annoying bug.
From memory you can't have the same driver name in 2 cars. I change the name by use of an extra space or underscore and works for me. If you go into the directory and delete your old .rcd (if not using it anymore) I think that works. (well it did for me, may need restart between del and re use) Hope this is helpful.