I was at Cars Land yesterday and managed to ride Radiator Springs after a 50 minute wait for Single Riders! The wait went by smoothly because we hopped into line at around 8:30 PM, and the weather was so refreshing and cool without the heat. Then, to make it even better, I ended up sitting next to my friend anyway, even though we were on Single Riders! (In comparison, Toy Story had a 40 minute wait.. just an extra ten minutes)
My brother said he managed to ride Radiator Springs three times though, all using Single Rider. Use that to your advantage if you can!