Smelly car? Don't reach for air fresheners to deodorize your ride. All chemical air fresheners do is mask the odor, not neutralize whatever is making the unpleasant scent. Many used-car dealers employ freshly ground coffee beans to make the car smell nice. Just leave a bowl of coffee grinds in the car, and let the odors absorb through them. The coffee acts like a filter, cleaning the air and absorbing the smelly particles right into the grinds. The longer you let it sit, the better it will work.