I recently traveled to abu dhab via road two weaks ago,it was a prettty trip specially drive.

You will get visa on Saudi - UAE border depends upon your profession in your QID. check with UAE Emigration Dept, Fly Dubai, Emirates Airlines or Qatar Airways the possibility of getting visa on arrival..its very important

Saudi Transit Visa QR 150/ passport
Saudi Insurance QR 10/ day (Minimum option is 7 Days [QR 70] ) * if you stay more than 7 days, its advisable to take 10 days; round trip (QR 100)

* Wear Abaya for women while crossing the Saudi Arabia, its a country follow sharia law. and womens are not allowed to drive in Saudi

UAE Visa - QR 108/ passport mode of payment card / cash * card payment will make the process fast otherwise you need to stay in quee

UAE Insurance - QR 10/ day ; * if you stay more than 7 days, its advisable to take 10 days;

Go ahead towards Abu Dhabi... Enjoy your trip