Subprime is defined as credit scores of 580-619. The highest grossing vehicles sold in the subprime tier are Nissan, Chrysler, and Hyundai. Subprime racing is when two vehicles financed with subprime loans race through a city with below median GDP per capita.
I went down to Crenshaw in South LA to watch a Nissan Altima compete with a Chrysler 200 in subprime racing. The Chrysler pulled ahead in the beginning before the transmission burned out and it stalled.