We've discovered the ability to paint the radiator curtain on the karts which have them. It is the same procedure as adding a bodywork paint.
First, create your paint and save it as RADIATOR_CURTAIN.tga and save it to the folder which all of your paint's files are located. Then, use PaintEd to package your new paint as normal.
Some pretty cool things can be achieved with this!
I encourage people to visit the SKM Forum and create accounts as we have new content and downloads, as well as a team of dedicated modders. We'll have exclusive content coming soon, and we're open to do jobs if there is a demand for it!
Download it from the SKM website! (http://simkartmodding.freeforums.net/thread/16/release-radiator-curtain-template")