Sorry, I just now got a chance to look at the video.
Take this with a grain of salt as it's coming from a driver of a momentum car. These are merely suggestions and I always tell people to try it both ways and see which way you prefer. At least if you TRY my way and decide that you like your way better, you've given it a shot and tried something new!
Turn 5 after the bus stop it seems like you're not using all of the track to the left there. One lap it seemed worse than the one prior (around 5:30 is the one I'm saying is worse than prior). On that lap, it seemed like you only came out to about halfway across the track and then started diving back in for turn 5. Let the car track out to the left and then stay out there a bit. Even for people that I saw getting out there and using that part of the track, they were still turning in too early. There is a point where you can see a traffic light. If you look for that light, there's a point where it'll intersect with a light pole behind it. THAT is where I was having people turn in. On the GTR last October the guy picked up another 5 or so MPH going into the laces when I had him do that