Car air fresheners come in a variety of shapes and sizes, but they all have one thing in common—they’re designed to make your car smell good as you head down the road. Some common fresheners are plug-ins, oil diffusers, aerosols, oil wicks, vent sticks, sticky gel fresheners, charcoal air purifying bags, and hanging cardboard air fresheners. The hanging cardboard fresheners are probably the most common and hold a strong enough scent to make your car smell good. They’re also relatively cheap. Vent type air fresheners, which contain oil fragrances and attach to the air conditioner vent with clips, are also popular and provide aromatic air to breathe. In the end, the type you choose for your vehicle is mostly a matter of personal preference.