Having got this yesterday I can confirm you will need to sink some considerable time into this trophy.
I have played all the Tour and finished that and I am half way through all the DLC packs and that is when this popped.
If you don't have the season pass and DLC packs you are going to have to grind this out redoing the tour or online events or single races.
My suggestion is looking for events to get accolades you need for the trophy “Credit Where It’s Due” as I am still working on that trophy.
That way you are killing two birds with the one stone.