Easter show in St Louis zoo park

I stumbled onto the show years ago going to the zoo.It is every Easter sunday at zoo park and you want to get there early.
It is actually two shows.It was all one show but I guess issues in the club happened and it broke off into 2 shows.VERY BIG SHOW has to between 700-1000 cars.
There is a upper and a lower section in the park.The uppers section you must have a fire extinguisher in your car or the will NOT let you in.The lower show is more relaxed and bigger than the upper show,and used to be free.Now the lower show charges to get your car into the show.
Here we go,this is the upper show.....http://www.hccmo.com/id14.html