But dont leave your car @ any shop and leave. Go on saturday morning around 7.30 AM, sit and watch what they are doing and what is the fault.

if you are leaving your car for repair, they might charge you more and say this parts has to be changed. So better be there until they find the issue and ask them show the fault.

Most of the shops in Doha are cheating the customers when you leave the car for repair and coming on the next day.