It is not necessary to have a 4x4 for a first incursion into
the "Empty Quarter", as long as you don't leave the road.
In fact, the United Arab Emirates have an asphalt road network
in perfect condition, giving partial access to the desert.
On the other hand, if you stop on the side of the road: be cautious!... Leaving the asphalt results in making a "splash" in the fine sand...
These Australian tourists have just discovered that.
I must admit that I made the same mistake too, at the same place, 30 minutes before!
Fortunately, a Saudi passing by with a "large" 4x4 pulled
me outusing a cable.