Is there some specialized websites for insurance comparison to help me choosing the best car insurance in GCC?

yes u can search on google

You can check with the following

http://www.souqalmal.com/ae-en/car-insurance

https://www.bankbazaar.com/insurance/car-insurance.html

can you tell me which type of facility you are looking means low premium, converge, network of repair and else then i can help you to find best company in Saudi arabia

well .................no idea on this pl

https://general.bajajallianz.com/MotorInsurance/MotorInsurance.jsp?p_type=BCI&src=CBM_055&utm_source=Google&param1=Compare-Car-Insurance-S&param2=Compare-Car-Insurance+Broad&param3=compare%20car%20insurance%20quotes%20online&gclid=Cj0KEQiA6bq2BRC6ppf0_83Z1YIBEiQAgPYNvfh8f3Xw-uKYU0Mvfp_ZsCfUs3-6gftPkhBolNsvIOEaAsz48P8HAQ

i think all friends here helped you