Similar to the other Expert GP suggestions, it's a hard race but you don't need to win everything. I used Toshiro's Wild Line as the new tracks are short with a lot of turns and it's faster to not drift on the earlier stages. Came in 1st, 5th, 1st and 1st.
First track being the Figure 8 Ball has a lot of transitions with S Curves. Keep up with 1st and 2nd place, drafting for the speed increase and the boost buildup so you have 2-3 at the end of lap 4. You can drift up the big hairpins to get a full bar but be careful on Exit. Top deck will require an early cut in because the track gets thinner before the tunnel to the left. Coming down to bottom deck stay around the180 mph mark drifting but end it for the slight left to boost for the finish line. It's a simple track and you'll get a lap done in about 25-29 seconds.
The Second one, Surf City, takes some learning. Drifting more through the big turns as with a low angle can keep up speed and get more boost. Track tips I've learned. Turn one is right at the start. Don't drift there and just keep in control for the chicane in the tunnel. For the 2nd turn in there's no visual clues for when to start turning in so try a few times in Time Trail. A good one will have you cut from the inside corner to the edge of the tarmac to the dirt and pylons. Perfect right corners of 3 and 4 can be drifted together before ending and then pulling a brake drift to the left for turn 5. Stop drifting around when you're about to pass the Sumo Digital sign on the right and when you regain control, boost through the chicane by staying to the right of the double yellows. You can take a straight path before hitting the long hairpin of 6. Brake drift is required to go right here but go flat out for the final direction to the left at the Finish Line.
Third track is Cargo Chaos. This is the easiest one so you can get over confident and spin yourself out on accident. With the turn 1 cut in at higher speeds let off the accelerator to drift right before drifting left. Turn 2 is the first hairpin that you'll have to brake drift through and keep your speeds up high. The double chicane through the cargo container is where you can get your best times. Go flat out through the Left and then Right before the checkpoint. Let off the accelerator as you turn right if you're carrying too much speed and then power out. Do another brake drift through the final 2 turns as to link them together and boost out for the bridge ending. I ended up driving so well that 2nd place was seconds behind and I was catching up to 7th and 8th on the bridge on the final lap.
Final track is Frozen Freeway and it's all about the Brake Drifting. First turn is a long hairpin that you brake drift into, as it ends do a quick flick to left and then right, you want to be near the center line at the checkpoint as quickly into the tunnel it's a sharper left. If you have boost use it through the turn as you can drive over the snow to a direct path rather than driving around it. For the Shipping Container turns start on the far left and brake drift right, you can angle this so you go from outside, inside corner, outside, back inside to outside then end the drift. Straighten out through the squeeze and start the right hand turn. You'll want to use the boost after the overhang as you turn right or you'll hit the outside wall. Continue to finish and if you have a boost available, cut in tight to drift through the inside snow. It will give you a shorter line at the same speeds.