Has anyone else seen this? I received the achievement in game and have attached both the badge and title to my Forza 5 gamertag. The Xbox achievement showed up in the Achievements folder after the race, but now it is no longer there. Also I am wondering if a gift car was rewarded for completion. I did not receive one. I did manage to squeak out 7th place bronze after being wrecked out three times.
There was no car or special credit reward for this Challenge, just the Badge and Title.
I don’t see it listed in the Achievements section of Xbox.com either, but it shows up when you look at Smartglass or compare with friends:
https://account.xbox.com/en-US/Compare/XboxOne/2067126551?gamertag=Mechberg
Thanks for the reply, ManteoMax!