In a previous life and a country far away, I used to fly gliders which has resulted in a lifelong interest in practical aerodynamics (I run a mile from the mathematics).
In the 1970's the mostly German, tadpole shaped fibre glass gliders, had made a huge performance leap from the previous generation of wood and fabric. Modern materials (carbon-fibre, Kevlar etc) have contributed to improved flying performance of current gliders but the aerodynamics seem much the same indicating that some sort of practical limit has been reached.

Similarly cars aerodynamics seem to have stagnated with a drag coefficient of around 0.3 since the introduction of the Audi 100. Of course there have been many individual backward steps since that time such as the VE Commodore (0.36) and SUV's in general (0.37 - 0.45) and some forward steps with dedicated 'futuristic' shaped economy models such as the Toyota Prius, Honda Insight (0.25).

Now do not get me wrong I think my Octavia 3 is great value and performs better in most areas than many more expensive rivals and is still my vehicle of choice. However, you would think that when they introduced the new Octavia 3, nine years on from the 2, that it would have improved aerodynamics over the previous design, but it appears not as they stayed at 0.3 for the sedan and 0.31 for the combi.

I did not really pick up on this as I considered the huge and practical interior was probably the price paid for the lack of change but two things have made me consider that Skoda have missed an opportunity
1) The Golf wagon is quoted with a drag coefficient of 0.27
2) Mercedes updated B200 models are quoting 0.25 and this is staggering because it is really a very ordinary looking large and high, 5 door hatch vehicle.
There is no exaggerated styling, cowls over the rear wheels, compromised internal head-room. Mercedes have achieved this with impressive figure with excellent (but not obvious) aerodynamic engineering.

Now I'm quite miffed, how does the Golf wagon get 4 points better rating than my better looking (imo) Octavia wagon and how on earth does Mercedes make a virtual van 6 points better?

The Mazda 6 and the Hyundai I40 wagons get around 0.27-ish but they are compromised inside, have more raked screens and pretty much dedicated two wheel drive designs, so their undersides are probably where most gains are made.
Don't be fooled by their vision impairing, rising side window lines as they contribute nothing aero, just the looks.

Nope, I beginning to think that Skoda may just have been a bit lazy in this area, what do you think?