No problems at all. Just don't forget to fill up your car before getting to Abu Samra. Also - don't count on ANY facilities neither in Qatar nor in Saudi. Once you cross the border to UAE, it is as elsewhere in the West.

The trip is absolutely safe, although boring - the 350 KM in Abu Dhabi is not a joke. I would advise to leave very early (around 5 AM). In this case you might get to Dubai around 2-3 pm.

Roads: in Qatar a big part of Salwa Road is still under construction - be careful. In Saudi - road is absolutely ok. In UAE - you'll see it and feel the difference.