In the spirit of the trend, Rocket League has added fidget spinner wheels to the game as an exotic drop with the option to be painted. You can see what the basic model looks like below:
Why, you ask? Why not? It's an easy way to grab a headline at the height of a trend and probably took less than an hour for someone to whip up. Personally, I think a fidget spinner topper that sped up when you accelerated would've been cool, but this is a good consolation prize I guess. Try to pick yours up today!