Driving over the dunes can be very dangerous, or either you know the way or can "read" the form of the dune or then you have to walk a lot to be sure what's on the other side.
So, to make my life easier I hired a guide. I must say that I was impressed with the way he knows and rides on the dunes.
Here is a video :
We took us to a very high dune, I was amazed that was possible to drive so high !
When we exited the erg, I was so impressed with the little moped that I asked the guy if he wanted to swap, he would drive my RR and I would try is Docker. I think we was so surprised that he said yes without thinking !