Tiny bug I know, but this achievement didn't tick over as achieved earlier this week when I got a part to 100%
I waited until after the race we had that day also, and still no update. A brand new version of the part now at 100% was also added to the car for that race.
Again I know it's a tiny bug, but when all you have remaining for the current season is to chace down an achievement or two because wins are out of the question, it's a bit annoying when they don't work ;)