I have two preschoolers that I ferry to and from preschool every day. Can you imagine how filthy the interior of my car is? There are food crumbs all over their car seat and on the floor. There are candy and chocolate wrappers, papers filled with "artwork" that they brought home from school on the floor too, and worse of all stains from spilled juices.
Is the dirty state of the interior of my car all my kids fault? Of course not! It is as much the fault of their mother who considers cleaning the car, inside and out, not on the top of her priority list as it is the fault of her children!
However, if I had a car vacuum conveniently mounted on the wall in my car garage and within easy access to the car, I would be more likely to clean my car more often!