The GoPro session was on the side of my helmet, so it got a ton of wind noise... If the rear camera had been working I would have used the audio from that (usually what I do) - that always works well.
Thanks for your comments on my lines - admittedly, turn 4 is my nemesis ever since I crashed there a few years back. Will try your line suggestion for coming onto the back straight - I've been experimenting to see what works best for me. Seems to be something between the 600 and 1000cc lines.