[ICECOLDKILLAK8]

pawn Код:

if(strcmp(cmd, "/paint", true) == 0)
{
if(IsPlayerInAnyVehicle(playerid))
{
  ChangeVehiclePaintjob(GetPlayerVehicleID(playerid), 0);
}
else return SendClientMessage(playerid, COLOR_RED, "[ERROR]: You need to be in a vehicle!");
return 1;
}

The J needs to be lower case and you dont need the vehicle ID in a variable

EDIT: Sandra said about the J first