[serialk11r]

I vaguely recall reading about independent tests when MB released the CLA (claimed 0.22), and it seemed like their numbers were something like 10% lower than what the wind tunnel showed.

That means someone has a measurement issue because driving the car in still air is going to produce a consistent amount of drag. However it seems like it would definitely be within 15%.

I can easily believe 0.16 (that's adding 10%) being possible with that shape. The XL1 is 0.159 without a full tail as well. Mercedes has gotten their minivans close to a Prius in Cd, so maybe there's a way to manage the drag there more effectively than most other OEMs have done.

Sending air under, instead of down the sides of the cars where the wheels will interfere is probably very useful. The Alfa Romeo BAT concept had (probably) poorer management of airflow around the tires, but with a bit more tail it got below 0.2.