In iLink mode you can only play with the cars available in the Arcade garadges. This is something we're all a little upset about. We'd like to race our modified cars against eachother, or even the Formula 1 cars. Somehow the saved garadges got left out of iLink mode.
I'm sorry to say that Loudmusic is correct (not that him being right is bad, he's actually quite bright ) Unfortunately you cannot as of yet pay with the Simulation cars in Ilink mode.
I wonder if anyone is working on a Gameshark hack.....