So, here's my detailed write up in order to try to help anyone still trying to do this impossible challenge.
Do not do this challenge if you didn't gold Lake Maggiore circuit experience.
I set the difficulty to normal. I tried every difficulty and I don't think it makes any difference.
I used DS4 on PS4 Pro, so this strategy might not work on PS5.
I tried many cars (Mazda, Peugeot, Mercedes, BMW, Porsche) but in the end I settled with Aston Martin DBR9. Why is that? Since it is the only (as far as I know) car in Gr.3 class which is actually GT1 in real life. This may not mean anything since by BoP - it has less power than the M6 (539hp vs 555hp).
BoP performance of DBR9 is: 539hp | 1250kg
Handling wise - DBR9 has a tendency to understeer and it is hard on its front tires, it has loads of torque so corner exits require caution since the rear does step out in 2nd and even 3rd gear.
It is of utmost importance that you gain P1 in the first 3 laps. Lap 1 is crucial, if you laptime is higher than 2:04.000 - RESTART. In this race every second counts, so just keep perfecting that lap 1 because it is really important.
I was P3 by the end of lap 1 with a laptime of 2:03.7xx. I gained P1 in 3rd lap, laps 2 and 3 were 1:56.8 and 1:56.9.
Lap 4 was 1:57.0;
Lap 5 was 1:57.6;
Lap 6 was 1:57.9;
Lap 7 was 1:58.0;
My fuel map was 1, I settled down on a 8 lap stint strategy. During those laps my slowest time was on lap 7, my pit entry fuel was 48%, I filled it only by 8%. Pit stop duration was 25 seconds.
Pit exit lap was 1:56.2. I entered the pits in P1, exited in P9.
Lap 9 was 1:57.2, position: P6;
Lap 10 was 1:57.2, position P2 (Supra, AMG GT M6 pitted on lap 10);
Lap 11 was 1:55.8, position P1;
Lap 12 was 1:56.8;
Lap 13 was 1:57.1;
Lap 14 was 1:57.2;
Lap 15 was 1:58.7;
I pitted again on lap 16, fuel was 1%. Pit entry laptime was 1:55.x, pit stop duration was 40 seconds, Hurracan pitted with me on lap 16. Pit exit position was P4, just behind AMG GT whom I overtook easily on fresh rubber by turn 4. However - AMG GT punted me off the track at the hairpin (turn 12). I barely managed to avoid spinning out, however I lost at least 3 seconds due to this incident.
Pit exit laptime was 2:00. Position P2 (due to the aforementioned incident).
Lap 18 was 1:56.2, position P2;
Lap 19 was 1:56.5, position P1;
Lap 20 was 1:56.8;
Lap 21 was 1:57.0;
Lap 22 was 1:57.5;
This time I entered the pits on lap 23 instead of lap 24. Pit entry laptime was: 1:55, pit entry fuel was 7%. I decided to fill up to 58%. Pit stop duration was 39 seconds. Pit exit position was P1. This is the key moment in the race. If you're not P1 by the 3rd pit exit - you can restart.
What we want, in order to have a good finish to the race without much pressure is someone other than AMG or M6 in P2 by 3rd pit stop exit, that way we will have the car acting as a brake which will be aided by lapped traffic. Those things will slow AMG GT and M6 down. During my race - R.S.01 was the "buffer" car and I went from a 2 second lead upon exit from the pit lane - to a nice 12 second lead at the end of the race. Which was fantastic since I took it really easy during the final 2 laps.
Pit exit laptime was 1:57.0.
Lap 25 was 1:56.0;
Lap 26 was 1:56.0;
Lap 27 was 1:56.7 (be vary of the lapped traffic, take good care overtaking them!);
Lap 28 was 1:57.0;
Lap 29 was 1:58.5 (at this point I knew I was going to win if I didn't make any major mistakes, so I eased the pace a bit);
Final lap was 1:59.7.
In the end - I found a car which suits me, found a style which suits me (all out attack mode) and used lapped traffic to my advantage. I had only 1 major moment, during lap 17 due to AMG GT pushing me off the track in the said hairpin. Other than that - the run was without major mistakes. During this race you can not afford mistakes. You absolutely can't afford overshooting T1 or the hairpin, hence my first bolded sentence - don't attempt unless you're good and confident on this track.
I hope this helps those who are trying. I couldn't wait for the patch, this was the final thing left for me to gold. This is an insanely difficult event, but it feels good when you win.
