TMNF (Steam): Can't change my vehicle's skin

[GodderDam]

Hi! I'm trying to bring new friends to TrackMania and booted up my TMNF account and found out I got a plain white car.
I remember I created this one skin back a few years. The problem is: I can't change my skin.

This is what is happening:
I navigate through: Profile > Vehicles
... here, the game is showing I have the BRA car selected. But if I go to any race, I have the plain white custom skin car.
So I navigate to: Profile > Vehicles > (page) 11/11
... and here is the plain white car, saved with the name of 'CAR'. Clicking on "Paint !" sends me back to the BRA car selection (not customization screen, just the car selection).
And if I try to customize any new skin and save it over the 'CAR' one, it says it's 'read-only'.
I tried looking for this file but couldn't find it. How can I delete it? How can I select and use the BRA car skin properly?

Any advices?

[Miss]

I think you'll have more luck asking this on the TM1 forum.