that's because the tube was designed for suction unit and the oil level can be checked from the instrument cluster (you got oil level sensor).

 

This is
You are the one, that had a chance to compare those designs and make final conclusion.
My guess is, that maybe BMW and Mazda didn't care about air drag and noise too much and didn't pay much attention to the shield. Or maybe Mercedes designing the panel put freshly hired engineer on it. Things happend.
My impression is, that you simply don't like new technology. Don't like electronic oil readout and want to get your hands dirty? Maybe you don't like remote door opener as well?
Than nobody will stop you from drilling a hole in the crankcase and putting the dipstick in it.
Than you can drill few holes in the door and put padlock latch on it.
Ops.. sorry maybe that would be too much

 

I don't think that my discussion with Kajtek is of interest to most of you. This will be my last post in response to him on the list. I will attempt to contact him off list. Please accept my apologies for this long winded exchange.