Being a mediocre player, I'm somewhat glad to hear others refer to using the emergency route through the final chicane.
I did it shortly after getting silver in S12 (Suzuka).
To get that, I A-spec'd the Suzuka 1000km race in the license test car, the Motul Pitwork JGTC Z, stock except starting on R1/R1 and switching to R3/R2 after a few stops. I had a bad first race (forgot to put enough gas in at about two hours, duh!), so I started another. Initially I intended to start at about 8pm, pause to do some PVR stuff at about 11pm, then race to the finish. But instead I restarted after 11pm, and so paused the game at about 3am in need of sleep. It was amazing how much better my lap times were after sleep. My best lap was a second below the silver benchmark (but didn't achieve the gold time). Also it didn't help that I mistakenly thought the race was only 5 hours long, not the actual six. I think perhaps I looked at my records for the B-spec of the Fuji race instead.
But silver still took me a few tries. I think perhaps R3/R2 is faster than R3/R3, (less understeer) or perhaps warmed-up tires corner faster than "neutral" test tires.
Having done that Suzuka test, I decided to take advantage of my track knowledge to do Mission 16.
I started off pretty dreadful in Mission 16, but gradually ate up seconds here and there until I could fairly reliably get to about 1.X seconds behind the first-place car.
And then I noticed the road through the chicane. A five-second penalty for some love-taps, but the chicane they let you get away with totally. And so I couldn't resist using it.
Good players (able to consistently come close to gold on S12) should be able to win this mission without using what is clearly a cheat, however.
I'm so bad at this game. Being in a Suzuka frame-of-mind, I gave Mission 26 a shot, but am consistently 4 seconds out. Waiting 93 seconds is annoying, too. The car for that is the same one as for the Tokyo Super License test. Which test I actually didn't manage bronze on last night, but I was getting sleepy. But that car and track will be my next project, I guess.
It's nice for players like me that this version of the game finally has prizes for getting all silver on your license tests.
Prior to this, apart from the easy missions (1-10 and 21-24), the only other Mission I had completed was the Suzuka East one, in the S2000. Nowhere to really cheat there; I just gradually got the feel of the car until I could eek out the win.