I surprisingly get a lot of people asking to detail their car. I never intend to make a business of it, but I love doing it to my cars and people ask me to do it to theirs. All it takes is a cheap orbital buffer (mines a used craftsman) and a shop vac. I normally get easily $100 for a basic wash/wax/vac, or $200 to remove scratches and polish then wax the car.
If you’ve got some free time and don’t live in the middle of nowhere, becoming a Lyft driver can be a very lucrative side hustle that allows you make money fast. And right now, they’ve got a promotion going on where any new driver will instantly get a $300 bonus after completing their 100th ride. If you start now and hustle hard on the weekends, you can probably unlock that bonus within a few weeks of driving (and that’s in addition to your normal earnings).