Ƙirƙirar wani nau'i mai mahimmanci na wannan jumla Ƙalubalen Liberty shi ne tseren Indy Pro Series da aka gudanar a kan hanyar hanya a Indianapolis.
Tabbas, wani nau'i mai rikitarwa na jumla shine "The Liberty Challenge wani tseren Indy Pro Series ne wanda aka gudanar a kan hanyar hanya a Indianapolis, daga 2005 zuwa 2007, a matsayin tseren tallafi ga Grand Prix na Amurka. "