Damn! I didn’t know it was even possible to win the last race with TT. Congrats!
Sub-30 is definitely possible. It goes without saying that minimizing crashes (especially with a car with poor acceleration like the Caddy Car) and knowing when and when not to drift are vital to the run. However, even if you practice each track hundreds of times you will still have to deal with the RNG of the other racers.
Getting caught in an opening clusterfuck (the start of the race where there are about 5-6 racers) will lose you so much time and even the ones that are ahead tend to meet you at bottle neck points.
I guess improvisation is key during these circumstances, but there are just some situations where you can't NOT hit someone.
But yeah, if you're a decent driver with incredible luck you can definitely get sub-30. My best is a 30:11 (emulator) on automatic which I've heard is slower than manual by a few seconds.