Congrats for finishing the event @michaelefw! Can you first make sure that you are currently logged in your Google Play or Game Center account? If your save data is still missing after that you will need to contact Firemonkeys directly for further assistance. You can do so at the following page.
I had this issue too one day. I also completed Snoop Dogg special event. However, when I launched No Limits again....the game showed that I had failed to complete everything in Snoop Dogg special event so I had to "return" the Ford Shelby GT500 Snoop Dogg Edition.
When that happened, I just force closed the game and launched it again. After launching it again, all of my previous game save data was back. That's also including the Ford Shelby GT500 Snoop Dogg Edition.
Try force closing No Limits and launching it again to get back your Ford Shelby GT500 Snoop Dogg Edition and your 150 Gold back.
