Review on 🚗 KFISI Car Air Purifier: Powerful Negative Ion Air Cleaner with True HEPA Filter - High Efficiency Twin Turbo-fan Captures PM2.5, Smoke, Odor, Dust - Noise-Free for Car and Home by Sherry Smith

I measured the results with a Fluke particle counter. As an engineer, I urge you NOT to purchase this product and instead invest in a very good quality air filter for your vehicle's HVAC system. This product does not significantly affect in-car air quality, (1) the filter is not a HEPA filter or anything like that, and (2) the airflow is so low that you will never filter enough air to make a difference.