The procedure is simple.

if the car is under company name / bank name you need to get NOC from them.

Then go to Al Asayel (B Ring Road) for Transit Visa of Saudi Arabia:
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Al-Asayel Co. Tel 437 2784 or 480 5606, Mobile 568 0914

Read more: http://www.qatarliving.com/discussion/saudi-transit-visa-agencies-30jan2...
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Make sure you and your firends can get UAE visa on arrival.

off you go ....

Take care,

Yasir.