Agree with others that its stupid not to supply one with the purchase of the car. Having said that I did get one off ebay and its been worth every penny. Around town I keep it folded down but when I hit the highway I put it in the up position. Keeps wife happy because hair is not whipping around. For me since I'm bald, hair blowing isn't an issue but just cutting down the wind noise and being able to enjoy the radio is nice. Easy to remove if you need to put someone in the back seat. Highly recommend.Ah ... That is stupid but ok. Do you have one? If so, do you think it makes a difference?