the 7k hp car doesnt seem to go into 10th gear by itself, so you could try to manually shift it into final gear. doesnt add stability, but might get you more topspeed?
The auto gearbox on the 7k car is super scuffed and constantly pinging off the limiter, id say you could get sub 7 seconds and a way higher top speed with manual shifting, more front downforce would do wonders for top speed stability. I also noticed you set the weight balance 100% to the front which I don't think was intentional lol