It may be a touch front focused, but it's a heck of a catch. ; No luck myself on that one on my one try so far!
I've rethought my strategy on some of the dark rides - I think I'll be resorting to manual focus for those very dark scenes as I've passed by so many trying to find something to get an AF lock on that I never got off a shot. ; I'm thinking better to get an underexposed shot and have something to work with in post, then to come back with no shot or a blurry mess, which is my usual for a shot like that!