I remember back in the early 90's we'd start a racing night around 6PM and we'd be running until 2-3AM ... just 2 heats and a main (10 cars/heat) ... that's how many people there were. And this was in a smallish town - the Metro areas must have been crazy.
I attended a national event once in Columbus OH ... WAY to many people. I think I qualified for the L-main (20 cars/heat) and if I remember correctly there was a TT-main. That's A LOT of racers - actually had the race start at pre-set times. You would show up at the track for your heat, then go back to the hotel room and wait for the next one if you didn't want to hang around and watch. After that experience I just kept to local events.
I ran just about everything electric - 1/12th (Assoc 12E - way back), 1/10th pan (started MRC Pro-10 ... eventually went Assoc 10L-SS), off-road buggy (Losi JRX2 - their first) and truck (modified the JRX2 to JRXT). 1/12th was THE class back then - sorted out the men from the boys.
A couple years ago I tried getting back into it. Took my Losi JRproSE buggy (sold the JRX2 for that purchase - circa '92-3?) ... people were like "what is that?" ... "that's the grandfather of your Losi XXX my boy." Managed to qualify on the pole for the B-main with it, but decided it was going to take some new technology to keep up (not to mention spares were NLA). I dabbled with a Trinity 1/12th for a bit, but it wasn't the best handler.
Tinkered with a couple 1/8th gas cars in parking lots (ancient and beat up Assoc cars) but there wasn't any racing interest for 1/8th where I grew up ... always wanted to do that though. Those things were wicked fast at the national level - esp the 4WDs.
I'll probably get back into it when my boys are a bit older in a couple years ... better start saving $ now (oh wait, I have Porsche ... what am I thinking
)