Sometimes.......tie your bag and put it NEXT TO THE "simple trash can"! Really people????? how hard is this?
When I fuel, or go inside for food or a shower I take my trash bag with me. For a trash bag I use the plastic grocery bags from a supermarket and I hang it on the passenger seat seatbelt latch attached to the seat so it sits between the driver seat and the passenger seat. If I eat something messy or aromatic like pizza, when I am finished I throw box and/or leftovers in a trash can right then.