I recently drove through Germany from east to west on my way back from our holiday. I saw trailers of cars from all german brands. VW, Audi, BMW and Mercedes. They do _not_ use covers.
On one trailer only the last car had cover on the front (didn't make much sense to me)
One trailer had a full cover on the first top car only.
All other trailers (i've seen about 10 I think) had no covers on the cars whatsoever. Nothing.
Someone else here recently said that Mercedes only transports cars in fully enclosed trailers. Not true, atleast not in Europe. Just regular old car trailers.
Also, some images:
No cover:
https://media.istockphoto.com/photo...car-transporter-picture-id689142184?s=170667a
Top cover only:
https://thumb9.shutterstock.com/dis...-new-volkswagen-golf-cars-along-729190612.jpg
VAG cars, full cover for front only:
http://www.whitesvehicletransport.c...0024-4edd-420b-b9fd-520be7047c4c-1024x768.jpg
No covers:
http://www.suncoastautotransport.com/wp-content/uploads/auto-truck.jpg
No covers, not even on the top front car:
http://www.bankgalerie.com/wp-content/uploads/2017/10/truck.jpg
No covers for as far as I can see:
https://nationalvehicledistribution.files.wordpress.com/2013/08/11-car-transporter.jpg
