File stucture for custom files, is there one?

[Skeleton]

Sorry not been around and dont know if this as been mentioned.
Is there a file structure for custom skin items on the pc in C:\Users\skeleton\Documents\TrackmaniaTurbo ?
Be nice to be able to mod the environment or skin a car or at least have your own signs.
Is any of the possible or have I spent money on something I cant even customise?

[TMarc]

Apparently it was not planned to have individual skins in the terms of self painted like it is possible with Maniaplanet.

[Skeleton]

I find this unacceptable
I bet I cant get a refund

[i7mean]

Well the actual system in Turbo isn't that bad... but not very much choice (pretty much 5 differents graphics with different colors ) and 1/3 of the possible paintwork are ... well ugly in my opinion