Build one of those DIY carbon filters.


I use mine as a Doob Tube for my bedroom (works like fucking magic with some fresh step cat litter in it), just put it in the trunk with the intake coming out the back seat.



I should mention, I use a 4" inductor fan to get airflow into the thing, it's hooked up to a lightswitch and 120v ac.


But I'm sure you can figure out how to hook up something to 12v dc current.