The extra drag is negligible.
Ehat amount of drag could they produce if theyre mot against the wind??
There will be essentially the same amount of skin friction drag since they don't add any additional surface area, and the form drag will increase a bit due to the additional width added to each fender, and the sight bumps on the seam. But, even if one did have the hundreds thousands of dollars required to put a full scale car into a wind tunnel the change in drag wouldn't even be measurable.
Just got through talking last night with owner of Hentury group about the vents your talking about, and we where working out a deal to buy both versions of fender vents, the one I have and this other version which I think looks cleaner, unfortunately since these are being posted on eBay my Chinese friend will not be getting an order from me, and I will just buy it off of eBay to enjoy on my car, I will no longer be posting about it, the venders here that spend their time trying to sell Chinese products are in for a rude surprise, and unfortunately many products are made in China, and they will sell to anyone with cash, there are 3 vents left on eBay.
I am not exactly sure I follow? Your upset that the Chinese supplier is selling these on eBay? You want to be the sole provider of these vents?
Did you ever get any pics of your car with the painted vents mounted?
