Go to doha bank, they give car loans without much problems.
but there need to be few things in mind.
1.The car have to be lesser than 4yrs old.
2.You need a bank statement of salary transfer.
3.Salary certificate from your company.
4.The car to be given by an authorized agency.But dont worry, if you pay a fees, any second hand car dealer will give you that service, even if you find a car by urself.

yes my friend, it is really hard in qatar.. for these little silly things
best luck!!!