Hearing that vacant lots could be put to good use, my husband and I started a small coin parking lot as a side business. At first, we were skeptical, but when we saw the unexpectedly substantial revenue coming in each month, we thought it would be a great way to supplement our household finances, and we laughed as we worked hard maintaining the parking lot's lock plates and signposts. One day, we noticed a huge, sweaty car parked in our parking lot...