Well I went back and found the two exits I was missing. It turned out both of them were in the Soda Jungle world. And one of them wasn’t even a secret exit, it was the regular exit! I had found the secret exit when I first completed the level and never actually did the regular exit. The regular exit just makes a path that goes in a pointless circle, so I guess that explains why I didn’t notice anything missing there.
So my file has all five stars and 94 exits on it now. And they’re the shiny stars too, since I never used the annoying Super Guide. Wow, I hated the annoying doorbell sound of that Super Guide block. I hope they let you disable it completely (so it doesn’t even show up) in future games.
I’ll still need to play around with the Challenges and Boost Rush modes more, since I’ve barely played them at all. They seem to be all about doing things as fast as possible, like a speed run. So it comes down to memorizing the exact route to take to shave a tenth of a second off your time, and performing everything flawlessly. That type of thing doesn’t really appeal to me, but I’ll give those modes another chance before I write my review of the game.