If I screw up a section, then I don't bother completing a lap, so I haven't ever actually completed a lap!
lol, i do that too. but sometimes, when i tend to continue, it might end up solving the mission. for example, at the vette mission at the infineion, i screwed up big time. understeered on the way up the hill, went wide, nearly spun. but i corrected, just gave it a shot and i completed the mission...