[Banana S]

Yes, it fits under the top perfectly. It's irrelevant at PCA track days because PCA doesn't require it. PCA doesn't care if you pass the "broomstick test" or not, since your top must be up while you're on track. I suppose it adds a measure of safety, though, if one were to flip.

One more point about the BK rollbar extension: Once the rollbar extension is installed, you must ALWAYS remember to close the latch on the convertible top when you put the top down. If you don't, the next time you close the roof the latch WILL catch the rollbar extension and will mangle your top for as long as you continue to hold the "close" button. It's in the installation instructions, but it bears repeating. It's never happened to me, but I can see it happening to someone else very easily if that person were to forget to close the latch.