Yeah I did too. I found it funny though that when the starting line says Monte Carlo, they're actually at Laguna Seca in Monterey, California. So, they posed the track as Monte Carlo. I think it was rather funny. Only true race fans would be able to tell that it's not really MC that it's in California. They did that as well in The Love Bug.
i watched it's a mad mad mad mad world in my art of film class, saw one of the turns when they were chasing spencer trace, i thought hey that was in herbie! and it didn't even connect in my mind that that turn in herbie was supposedly in monter carlo
Herbie Rides Again had one race in it, though it wasn't really a major one. When Ken Berry & Stephanie Powers are in Herbie and he goes to the race track. And Ken Berry is terrified.