The Syoryu's illegal conversions should be the other cars like the Bugatti Veyron, the Chevrolet Caprice, the BMW M5, the Ford Escort WRC, the Mitsubishi Lancer and other ones available at his website and at MMArchive.Syoryu is an illegal converter? I thought he asked for permission the original author of the D1GP cars?
About the D1GP cars pack for Racer, the author has said that you have the free permission to convert the models for other games. Check this topic at MMArchive forum and the link to the info about the pack.