Until the next GMZ trainer comes out, a temporary solution does work using older trainer/hacks, RTD+Bot by darkteam & NFSW trainer 1.2.9.
Launch the game, launch RTD+Bot, click STHI, launch NFSW trainer 1.2.9 click any of the hot key combinations you want.
At the end of the race you do receive Rep & Cash.
The gems are showing up for Treasure Hunt.
This is the same temp solution that was suggested a few patches back, I don't remember who came up with it at the moment but it still works today.






