Rover 400 Tourer Pollen Filters From Sep 1993 to Nov 1998 Available Here. Pollen Filters Available Here. Most people don’t know that they might not be breathing in clean air while they drive. Pollen filters are not as soft and unnecessary as they sound; they are responsible for keeping debris and pollution from entering the ventilation, heating and air-conditioning system of your car. Without them, you’re more at risk for developing asthma and suffering from nausea, headaches and fatigue because of the dangerous amount of pollutants around you. Pollen filters are typically paper or active carbon paper filters that attract dust, particles and chemicals. It’s recommended you change your pollen filter at every major service or roughly once a year.