al slam alekm
to get KSA transite visa you have to give your passport & those going with you passports & your car registration card & photos to the some offices they will take 350 QR & they will send somebody to the Embassy to issue visa

there is office on ummguelina area called alassayel & one on ma"ether street & one after horse racing roundabout

but note that you have to get release paper from the bank if your car not yet register under your name(pawned)because the qatari border will return you if you havn't the release

thanks
regards