I have found a really good explanation->

The problem is, its on german ;D

but here is the link->http://mistraltweety.siteboard.de/mistraltweety-about173.html

The MHD-clan have made a carskin video. watch it!->http://www.youtube.com/watch?v=e-NexSkTBbQ

for more questions please ask ZatRot.