You will have the exact car wreck and data centre locations on your map. You can only 'refind' car parts by following a sequence you set for yourself, as to not to revisit parts you've 'found'. You can just skip the mission you're having trouble with, that could take away your determination. Especially tiresome if you retry missions to get a better medal. If you have all starter cars, you must go through removing car parts, and each time you win a mission, go and equip the exact car part, having to remember what part you won. Even if you do not buy other starter cars during your career, you can do this only three times maximum. You can, for sure, buy a different starter car, clear your perks and run the story along with your friend at the same level. If you really want to restart from scratch, you can purchase one of the beginner cars, clear your perk points and do just that. You can run all missions again, you can see all cutscenes again.
