To keep the rear clear, you need the air flow to adhere to the surface of the car in an almost laminar fashion. The Yeti shape at the rear makes this neigh impossible.

Spot on. Hence my Audi A2 with its Kamm back tail and the perfect teardrop shape had a clean rear window for 9 years with me and that is WITHOUT a rear window wiper! The Yeti's rear is constantly dirty and sans a wiper we might has well have been driving a van! So thankfully it has one of these!

Perhaps I might try taking the rear mudflaps off and seeing what effect that has.

The best car I ever had for clearing the back window was the old Skoda Rapid. Anything over 30mph and the wind over the car immediately cleared the rear window.

My link

Edited 1 April, 201115 yr by Llanigraham

Perhaps I might try taking the rear mudflaps off and seeing what effect that has.

The best car I ever had for clearing the back window was the old Skoda Rapid. Anything over 30mph and the wind over the car immediately cleared the rear window.

My link

It is quite clear from the drawings why too: The shape of the roof and rear window closely resemples the upper surface of a lift body (air plane wing or sail) and the little lip on the rear edge of the hatch defines where the top of the vortices behind the car are. Result is a closely adhering flow across the top and down the rear window - but then it is no longer possible. The vertical surface of the rear hatch probably got quite dirty in the rain?

Edited 1 April, 201115 yr by Agerbundsen

The vertical surface of the rear hatch probably got quite dirty in the rain?

Funnily enough it didn't.

I wish I'd kept that car. We gave it to Sheila's sister and when it had a small problem her idiot mechanic boyfriend refused to repair it and scrapped it! All it needed was a simple job! It's what brought me into the Skoda fold.

It got rallied and trialed and generally hammered. It is the only car I was ever stopped for speeding in and got away with it. Oxfordshire's best didn't believe the figure they had recorded (100+!!) It was a "bit" breathed on.

There's an £8 'sort of' solution... an official Skoda part.... Bumper foil

It takes 5 minutes to fit (just 2 self tappers) and provided you remember to fold it into the car BEFORE you close the tailgate, works very well. It's not the most durable material, but even if you have to replace it each year, it's money well spent because not only does it stop your trousers/skirt (delete as appropriate) getting mucky on the bumper, it also protects the bumper itself from knocks & scrapes from Golf Clubs/Prams or whatever other sharp stuff that people stick in the boot of their cars!

It works best on cars with the raised boot floor, but I'm told it's still worthwhile on cars with a low floor & no spare.

(A Slightly tongue in cheek sort of reply!)

Edited 12 April, 201115 yr by speedsport

Not quite what we are talking about, but it does look good for what it is.

What this thread is about is an aerofoil type moulding above the rear hatch that "might" keep the back of the car clean and stop the dirty spray collecting on the rear hatch and window.

Not quite what we are talking about, but it does look good for what it is.

What this thread is about is an aerofoil type moulding above the rear hatch that "might" keep the back of the car clean and stop the dirty spray collecting on the rear hatch and window.

As it happens, I have never found the Yeti to be excessively dirty at its rear end, so to speak! There are many more filthier beasts about.

I'd a Golf GTi that was dreadful, awful! I have been quite pleased with the rear window of the Yeti so far!

It's been a while since the latest post in this thread.

I wonder if someone took the odd chance and actually bought the Superskoda Roof Spoiler

http://www.superskoda.com/Skoda/Yeti/Skoda-Yeti-roof-spoiler-SPORTIVE-by-KI-R-V2-TÃœV-version

Like so many others I am little bothered with spray almost glueing itself to the rear window of my Yeti.

I do appreciate all the thoughts about aerodynamics, but practical experience outnumbers any scientific theory I think.

So - once again - did someone try it out?

And - if so - what was the result?

I find that the top part of the window is worse than the bottom part.....can be quite hard to clean using the rear wash wipe.

Search is your friend:

http://briskoda.net/forums/topic/199875-yeti-roof-spoiler-fender-flares-dashboard/page__hl__spoiler

tom