Turn off all assists and set the lap count to the minimum of 3. Vehicle should not matter although I used a 2017 car rather than a classic. For circuit I would recommend picking Austria due to the short lap, long straights and large run off areas or one of the 4 new short circuits.
2 additional theories if you are struggling:
I had flashbacks on (although I didn't use one) so it might be the case you can use them if you spin/crash.
You could likely drive slow enough to complete your first lap once the AI has finished race (allowing them to lap you twice) reducing the need for you to drive 2 extra laps.
Hope this help still someone.