Having had a new Octavis Estate 4x4 for a week which replaced a similar model I lowered the nearside rear window at 45-50 mph and the vehicle felt as though it was falling apart from the vibration.  The radio was difficult to  hear until the speed came down to 30 or so.  You could not in the summer have the window down because of the noise.  Has anybody got any ideas? If it cannot be improved it is going back.

 

John

Is the noise from the wind? Or some other type of noise? You could open the other rear window a smidgin to relieve some of the vehicle pressure.

its normal and its been like that since the mki octavia with the thunping with the rear window half down.  there is a thread somewhere on here that explains why it happens with some physics explanations!

Are you sure it's not the air pressure difference due to wind buffeting? Did lowering another window help?

I had the back window down the other for the first time (I've had the car since September!) and it was pretty bad. I rarely have only one window open though and I'm planning on getting the wind deflectors which should help.

That is perfectly normal and will be the same in any car. When driving with back windows down they make this 'thumping' sound because of the air tightness of the car's cabin. Google it.

 

Roll your front window down and it will go away.

A few years ago now, I was in a mates car. We were on the motorway with only the sunroof open. We were suddenly aware that all the air was being sucked out of the car as we were both getting very light headed.

The noise was also horrendous but that was the gothic rock on the stereo. Ha.

Opening a window cured everything. I think it was a vauxhall.

I had the mesh panels installed on my rear windows, outwardly it looks like you have heavily tinted windows. With those installed, it completely solves the 'thumping' sound when a rear window is down.

 

However, I very rarely have need to lower my windows, it's air conditioned

 

So there you go, a possible solution is buy window blinds/mesh for your MK3.

Wouldn't have cured the fact that it was a Vauxhall though

Thanks for all the info.  With both rear windows down it is a little worse but goes if I drop the front ones.  Even so  it should not be as bad as it is surely.   I do get the same with the sun roof open on the Landcruiser.

Thanks again

John

An obvious reason to reject the car! Damn physics...

Who'd be a car dealer...