This race can be found by going to Showcase Events -> Passing Challenge -> Ferrari LaFerrari Challenge
The Ferrari LaFerrari is a hypercar which is RWD and features over 900 hp between a naturally aspirated V12 and an electric motor. With a mid-rear engine placement, it has great balance but can oversteer wildly if you're not careful.
The cars you need to pass are 1960's Mini Coopers. Have rewind ready, because you can smash into one of these cars before you even noticed it was in the way. It is also worth suggesting switching to a follow camera since it will give you more down road view.
You need to pass 88 of these cars in 2 laps on the Monza Circuit to complete the challenge. I passed about 43 cars in the first lap and 45 on the second, so go for 44/44 split. Good luck!
EDIT: the number of cars you need to pass changes with difficulty. Mine was 88 on PRO difficulty, so it will be less for lesser difficulties. Plan your split accordingly!
EDIT: It appears that you should try your hardest to run a CLEAN race to get this one to pop. There may be other achievements which follow this oddity.
Please let me know if there's anything I missed or any way to improve this guide!