Saw several races at Riverside, a Can-Am during the 5 liter, ground effects era, the IMSA 6 hour, and an AMA bike race. Kenny Roberts won 750cc GP and Cook Neilson won Superbike on a Ducati, about the only bike that didn't wobble coming off a corner. The AMA didn't care where you watched from as long as you weren't right on the track, so we went right out to the Armco. I could almost read Roberts' instruments as he went by. When he wasn't on track his 750cc Yamaha stood in front of his garage with no one around it except one mechanic against the back wall in a lawn chair. Imagine F1 or IndyCar leaving a top level car virtually unattended.
During the Can-Am I was shocked to discover the body side fins that supported the wing were made of that super exotic material...marine plywood. I was also shocked at how high they revved those small block Chevvies. When they first came out to practice I kept waiting for them to shift and they would just go a couple thousand RPM higher.
The 6 hour featured a fascinating duel between a Porsche 935 and a Lola T600. The Porsche was an absolute rocket down the long, long straight, but the ground effects Lola was much quicker through the corners, particularly from turn 1 through the esses and up to turn 5. Every time the Lola had to get by he was forced to pass the 935 several times, gaining just a little ground overall with each pass until he could finally make it stick. Then he would pit and the whole process would start again.
I really miss Riverside.