Thanks for playing! Haha I am glad you liked the wheels!
For the parallax background I followed this tutorial https://kidscancode.org/blog/2017/04/godot_101_12/. I think it is for an older version of Godot or something though because it took me a little while to find where some of the properties mentioned in the tutorial were located. Basically in the "Repeating the Background" section it talks about editing the background texture flags to include repeat. For this you need to edit the import settings of the backround.png file in the Import tab in Godot. Then for the region you have to select the background sprite in the scene tree and edit its region property in the Inspector Tab. Hope this helps! 
