Maniaplanet Forum

I see that folder
K:\Documents and Settings\User\Documents\ManiaPlanet\Cache
has 5391 files inside (webm, gbx, zip, ogg, png, jpg, ....) and occupies 6.5 GB on disk (K:\ is the drive where I have installed ManiaPlanet)

May I safely remove all those files without messing up Maniaplanet (Canyon, Stadium, Lagoon, Valley)?

Yes, you can safely empty this folder. The side effects you will see in game is that the game might start & close a little faster, and your game will have to re-download vehicle skins of other players.