There are definitely some gray areas of what goes here and what goes in the other thread, but the rule should be, if you didn't know you were going to see it, and you get that "wild spot" feeling, and you think the rest of us may be able to share that feeling if you post it here, then it goes here. If you knew there was going to be a meetup, while still great to see, it doesn't have the same punch as spotting something unexpectedly in the wild, and goes in the other thread.
Dagger's above spot of the 15 Chevies is a good illustration. I'm sure he didn't expect to see it, it's not obviously a car show with a bunch of guys sitting in lawn chairs behind their cars, and I think most of us here would agree that's a valid wild spot/mega spot. Plus it helps that he didn't go through and take photos of each and every car and post them, that would get a bit boring, while the single group shot is pretty cool.
Okay then.
Also, are my previous Sunday photos violating the rules?
I never got the feeling they were over the line... I spot a lot at places where I expect to see good cars like country clubs and mall/restaurant valets, and while not as exciting as, for example, seeing the Ghost in my neighborhood yesterday, which is totally unexpected, you're still not sure you're going to see anything... Those previous photos all had that feeling to me. It also helps when you don't have a bunch of other people in your photos standing around with cameras waiting for the cars to drive past...