Octavia Sunroof

[Rosie]

In what seems another lifetime I owned a BMW E30 325is. The sunroof functions were the same as the current VAG roofs. The only differences were that it was a metal panel, not glass, and there was a 40 or so mm tinted plastic flap across the front of the opening that automatically popped up once the roof was opened more than about 1/3 of the way. These flaps was common on many older style sunroofs, many of which had much bigger openings than today's sunroofs.

The flap was there to create a low pressure area behind it, making the air presure inside the car higher than the air going over the roof opening (think leading and trailing edges of an aircraft wing). Result - no annoying air buffetting, whether on Autobahns, on Europes 130kph motorways, or driving the kids to school. There must be a reason that engineers have phased the flaps out, but aside from cost (which companies generally aren't shy about passing them on to consumers) I can't figure out why modern cars now have air buffetting, and their 30 year old predecessors didn't, and all for the sake of a cheap piece of plastic and a couple of spring loaded hinges.

[woofy]

Rosie, those hinged flaps are still there, I've had them on an aftermarket Hollandia which was huge compared to the VAG one, and the VAG ones have them with ridges in them. The buffeting usually only happens at one speed, I've found in all cases its around 30-40km/hr. You really have to be sitting at that speed consistently...and it would only be once in a few months I do that. There is also the comfort setting where it doesn't open all the way, that is the setting where no buffeting should happen at all. With it open fully you get the slight affect at a certain speed, but not anywhere else so I leave it right open.

I've found the VAG one barely noticable, my Hollandia being a lot larger had a more obvious/painful effect.