On another note, I added this under the car today:
The valve with the red tap will allow me to manually drain the oil catch can when I'm at the track, so it's really convenient (there is already a 'sight' on the side of the catch can so I can see when it needs draining). It only ever fills up significantly when I'm at the track, so it's better for me to drain it manually instead of plumbing a drain back to the sump. Also it will be good to see how much oil is going into the can, and what it looks like, before I drain it.