There was a well remembered incident, on the South Coast I think, where the bass player put his instrument on its side on the floor behind an upright piano. You’ve guessed it, the piano fell backwards and flattened the bass. I know the bassist but I wouldn’t bring up painful memories.
As above, if I can’t find a corner - and most time there isn’t one - I put my bass on its ribs. Once I’d just got off the stage at the half time break and I heard a splintering noise as the sax player walked in to it and put his foot through the table. Only a small split but it still cost a grand at a well known firm of bass makers/purveyors.
A stand is good but it’s an extra bit of metal in the car and intrudes into my playing space, not generous at the best of times.