Well after a month or so of not much photography (except family/kids stuff and a few random shots mixed in), I'm going to another CCS Motorcycle Club Racing event this weekend on Sunday, and will be better armed than before.
I've rented the Canon EF 100-400L and the 1.4x TC III TeleConverter which should be here on Friday. Will be doing the firmware upgrade for the 6D tomorrow night or Friday to get the f/8 autofocus and will be in business with 560mm setup for the track!
Any words of wisdom?