NAEture's Car Air Freshener Diffuser(Sneaky Link)

Glass diffuser filled with exotic essential oils . 
Diffuser comes with a safety cap . Remove the safety cap , slightly tilt bottle to wet the cork like top . This will allow the oil to saturate top and evenly distribute fragrance throughout your vehicle. 

Diffuser with oil will last  45-60 days . Comes with a 1 oz refill which can be used for your home . Simply add 2 -4 droplets depending on your pot (w/water) or your oil burner. . Bottle will last a life time as long as there is no impact to the glass .