Why have the Automakers refused the boat tail design?

[ron22]

Originally Posted by Big Dave

"There is no reason that the rear axle could not have a much narrower track and be farther back in the tail."

Big Dave says:
Ever tried that in fresh snow?

Yes I have my friend own a Gen 1 Insight.

[NHB]

Originally Posted by euromodder

They have good Cd values when compared to other cars, but it's simply not good enough to make much of a difference regarding fuel economy.

We're still hovering around the 0.3 mark, with the better vehicles around 0.25 - and have been for many years, the A2 is old.

To make a real difference, we need to get to 0.20 - and below.

What do you think about those designs taken from your link (especially Mercedes "boxfish")? I see them as a much more practical designs than a long boat tail. I don't think that a jump from 0,25 to 0,20 as a revolution. It's just one big evolutionary step which can be compared to weight and rolling resistance reduction.

A2 was ahead of it's time in many ways. For me A2 was a pure eco design, whereas new Mercedes A-klasse is just a normal compact car with atractive and sporty design. IMO that shows some clear improvement. It's interesting to see what the next A2 will bring.