I don't have a car, so don't drive to Audax, though I have from time to time considered hiring one. If I did have a car, I'd probably use it and do more calendar events. The only non local (less than 50 miles) events I've managed to get to on the same day have been evening starts and the Double Dutch, that's despite living spitting distance from a busy mainline station.
So, I only do a few calendar rides (Never more than ten in a year), stay over, ride at least one way (Sometimes as a DIY) and make more of it, I am an Audax tourist.
I did once accept a lift home and embarrassed myself by not knowing how to get there without using the cycle paths, I'd only lived here five years and the ring road was a complete unknown to me.