need help creating custom skins

[Airwreck]

Hello,

I just finished my Skin for a Porsche 3.8 Cup, but whenever i want to look at it ingame, its pure white, nothing will show.

I exported the file as a .dds file in DXT1 (or BC1)
I also tried to export it as a DXT3 (BC5) .dds file, but that did not work as well
I also did the XML file thing, not 100% about that but it looks right from what I saw in other Skins

Thanks