I'm mobile and use a hive pot and only had one accident, albeit a bad one where bag, towels and accessories had to be binned. I changed my taller bag to a sports bag, one with pockets either side. Wax pot goes in then towels and plastic that go on work table go to side of pot to wedge in that way, empty space I then put my tupperware that I use as mini bin for strips and sticks during wax. beside that i have another rectangular tupperware which has tweezers, small bottle of surgical spirit, some strips, cut strips for brows/lips, some cotton discs, tissues and some spatulas. On top of tupperware I put my towels for covering table during wax and this also creates good wedge effect for wax pot. One pocket has bigger bottle of surg', spare spatulas, cotton wool discs, pre and after lotion and strips. Other pocket has jasmine oil, gloves and bag that holds my lash tinting kit.
I put the bag in my boot only, never on car seat and I NEVER allow anyone else to carry it for me. I don't care how careful my husband or clients promise to be when carrying it I only trust myself not to swing it about!
I tried roller system many years ago but 2 different machines broke in quick succession, as said that was years ago and I'm sure the roller system is much improved and can cope better with being switched on and off frequently now. But I love my hive pot and am a speedy and good waxer so not too inclined to change.