Volvo is experimenting with a system that will take car interior air filtering to a whole new level above today’s common dust filters and the fume filters found in ritzier car models, the New York Times said. The paper said the Volvo air-filtration system, well into development, not only cleans the cabin air better than any other car's does now, even in the confines of a tunnel, but works with the car turned off. It is also self-purging, which means that unlike conventional filtration systems, it does not need regular maintenance.