Laudgi7,

A colleague of mine did that and the procedure is that you need to apply for a visa at the saudi embassy in Qatar, which take about a day.

1) Make sure to take an arab speaking person with you
2) Tell them you will travel by road
3) Make sure that it is written in the Visa
4) You will need 2 visas one to go and one to return
5) You will also need to get a visa from UAE embassy in Doha to travel by road.
6) Int'l car insurance.
7) The total road journey takes about 7 hours travelling at 120 to 160Km, and there are cameras on the way.
There are facilities along the way,

Safe journey

Angelo