Mobile Car Wash. . . *SH/SB
What makes this #sidehustle popular, is the way you promote it. Sure you can go door to door or post flyers at the local gym to drum up business, but I think we're way past the numbers game and/or waiting for the phone to ring.
So, a couple of profitable ways to promote this side-hustle is to offer it to business owners with 50+ employees as a perk to their rewards program or as an incentive to boost attendance. This also works well with new/used car lots. This cash cow only requires access to water and a few simple supplies: soap, bucket and a sponge. The BO provides the water and all the action happens in the parking lot. It doesn't get much easier than this!
To stir up word of mouth referrals, offer the referring BO's $5 cash per car for every business he refers to you, as services are rendered and $5 residual, for as long as the referring BO uses your service. So, if you wash just one car an hour for $30, that's $240 in an 8 hour day. At this rate, 50+ cars would keep you busy for approximately 6 business days. That's $250 fee to the referring BO plus $250 residual thereafter and a whopping $1190 in your pocket! Not bad for a side-hustle.