Cloudy Mango Crème Hanging Car Diffuser

The scents are very nice and the diffuser is pretty but they give me a headache if I use one while I'm closed up in the vehicle. I plan to remove the freshener before driving and put it back when I return. Probably will leave just enough fragrance that way. The plastic stopper is so tough to remove. I realize it keeps the liquid from leaking for shipping but without a tool or strong fingernails, it is a challenge to remove.