This is a review of the routes from 2010 , so there may have been improvements.
With my 2005 , 5er , in 60,000 KMS of towing before I got on those routes ,I had never had any breakage of dishes or anything in the RV , UNTIL I drove those roads.
Also the only route I've ever been on , where signs warn that there can be waves high enough to wash your vehicle off the road.
Spectacular views if the weather is good ; BUT !
We traveled after Labor Day and a lot of the parks were already closed.