Pretty simple on the surface but can take a bit of time to get to in career mode, Basically once you join a WRC team (Hyundai, Toyota or Ford) you'll unlock season objectives which vary based off what specialty the team might focus on (Performance, Crew...etc) This only needs to be done once and can be done on the first rally. Mine was finish 5th or better in a rally which is easily achievable on standard difficulty (100% to be exact)