Here's your answer: Supercheap Auto is owned by Super Retail Group Limited (ASX: SUL), a publicly listed Australian retail company.
Repco: Owned by Genuine Parts Company (GPC) through GPC Asia Pacific, a large American automotive parts giant.
Autobarn Australia is owned by the automotive aftermarket company Bapcor Limited. Bapcor also owns other well-known automotive networks, including Autopro, Burson Auto Parts, Midas, and Opposite Lock.
Pedders Suspension & Brakes is a 100% Australian, family-owned company managed by the Pedder family (until they sell out to an American hedge fund mob).