Hi,
Well if you car is earlier than 2004, you cannot import it to Doha. I suggest you ask your best friend to sell in dubai itself. You need to cross Saudi Arabi by land and you need to take insurance for Saudi and Doha....it is going to cost much...the roads i heard are quite dangerous with big trucks.
I imported my 2004 car from Dubai and registered in Doha costing me about QR 8000 by ship. Inspections are more stringent than Dubai.
Hope it helps.
Reg
tkp
Doha.