I had the 1/32 scale open wheel Indy cars. HO was just to darn small. The 1/32's fell out of favor to the 1/24 scale since there were tracks you could take your cars to. That use to be big business. I remember the AFX cars were the HO whip! A friend and I combined a HO car track with a HO train track. We had lots of fun making the crossings.