Wind deflector.

[Smartbear]

Go for the windblox wind deflector version, it's the winner.

The oe mesh deflector gives less turbulence than the solid versions, it's why bmw chose the material
Rob

I wouldn't think so. The mesh windscreens let wind leak through, whereas the sold body windscreens completely block the turbulence.

Then you don't understand how it works, the oe mesh deflector reduces cabin turbulence because it allows a small amount of air through! That's why bmw chose that material.
Rob

[firebobby]

The oe mesh deflector gives less turbulence than the solid versions, it's why bmw chose the material
Rob

I wouldn't think so. The mesh windscreens let wind leak through, whereas the sold body windscreens completely block the turbulence.

Then you don't understand how it works, the oe mesh deflector reduces cabin turbulence because it allows a small amount of air through! That's why bmw chose that material.
Rob

+1

[Chris_D]

I wouldn't think so. The mesh windscreens let wind leak through, whereas the sold body windscreens completely block the turbulence.

Then you don't understand how it works, the oe mesh deflector reduces cabin turbulence because it allows a small amount of air through! That's why bmw chose that material.
Rob

+1

+1
And that youtube vid on the windblox site for the e85 is just laughable. Has a solid deflector in place but the side windows open. Bonkers. No wonder that old git doesnt look very impressed / not so talkable. Excrutiating to watch as he's obv coerced into saying things he doesnt really believe. But they still used that vid to promote it. Hhahaha

http://www.windblox.com/bmw-z4-2002-200 ... sponseTab4

[enzed4]

Go for the windblox wind deflector version, it's the winner.

The oe mesh deflector gives less turbulence than the solid versions, it's why bmw chose the material
Rob

I wouldn't think so. The mesh windscreens let wind leak through, whereas the sold body windscreens completely block the turbulence.

I agree with Smartbear. BMW has gone with a mesh design for a reason. Here's a quote from a company that makes (or made) wind deflectors that sums it up better than I can:
"When driving with the roof down low pressure forms inside the car, pressure builds up outside the car as the speed increases. As the high and low pressures try to equalise, turbulence forms. A well designed wind deflector reduces and controls the turbulence by disrupting this process.

The design and materials used to disrupt the turbulent air must be carefully considered. Any attempt to 'stop' rather than disrupt the equalisation process can create turbulence elsewhere.

Deflectors made from solid materials (as opposed to mesh) in an attempt to 'seal' the cabin to prevent drafts from the rear can work well at low speed (30mph or less). As speed increases the equalisation process kicks in, often causing the air to 'eddy' over the driver/ passengers' heads. As speed increases so too does the pressure on the wind deflector structure."
So, the view appears to be that at low speed, a solid deflector is perfectly fine, but at higher speeds it directs the airflow back into the cabin around the arms/feet. The mesh deflectors are designed to allow some airflow back into the cabin (around the neck/shoulders) without the noise/turbulence experienced with the solid deflectors.
As always, it comes down to personal preference, both do a similar job with slightly different results.