I gave a ride today to some lady and as I was driving she told me she spilled some water from her bottle onto my back seat. She apologized and offered to go inside, get a towel and clean up the mess but I told her I'd take care of it. As I was wiping up the mess after the ride ended I noticed she had given me a $10 dollar tip in addition to my $6 ride. She was smart to give me a tip to avoid getting a cleaning fee tacked onto her bill. But whatever her motivation it was nice to see her do the right thing and pay me for my trouble.