Yeah, I'm going overboard with the unpleasant possibilities, but still
Dude!! ya think?? well maybe..
As for me, I have done some driving in the not to distant past while riding my aneros prostate massager.
Like anne4joy I agree , that a plug is the best bet, and a through clean out. Like Switch,,,, NO AIR.
The beauty of knowing your system, and your schedule(BM) is that you can get cleaned out well prior to your excursion.
Lube really well, and be able to relube on the road trip. Oh,, are you traveling alone,, if so,, that is good. You can wear actually go naked from the waste down , lean your seat way back, and put your left leg up on the dash, put car in cruise control mode,,, and this way you can manipulate the plug or toy at will as your region will be accessible!!, it will be exciting... YOU HAVE TO BE A EXCELLANT DRIVER TO DO THIS, LIKE DUSTIN HOFFMAN IN RAINMAN.. if you cannot multi task well, and are an inexperienced long haul driver, you will learn fast,, have a blast....do the speed limit plus 3, go with flow, don't draw attention to yourself,,, Relax enjoy....