I really like this car diffuser. Unlike other reviewers, I would definitely recommend it and am purchasing another one for my Mom because she loves mine. I use Mountain High in it and add about 10 drops every week or two. I don't find that I notice the smell that much while I'm driving, and it definitely does fade, but my car always smells fresh. If you are looking for a full on diffuser with a potent smell every time, then this may not be the product for you. But if you are happy with a gentle scent that you can control (vs other store-bought car scents), then it's the best!