Pop Caps: The yellow one is used on WMS Grand Prix (and I would assume a couple other WMS games of the era), the helmet dude is from WMS Gorgar, and Flash is from WMS Flash (obs). Can't place those racecar caps.
The big clown is a promo piece from the WMS Cyclone plastic set.
The big ass flippers are from CCM Big Flipper.
(EDIT: the car pop-bumper cap is from WMS Tri-Zone)