Hi @Islam Soliman I think Dubizzle is not perfect, but also there are not that many alternatives. If you follow the main principles of not chatting outside the Dubbizle chat area or providing your bank details, nor engaging in conversations with potential buyers that don't even live in the UAE, you should be ok.
See below some more info:
I've heard about Dubicars, Bayut, etc.. but i am afraid all are same concept.
Another option is to visit car dealers but that's usually even much more of a headache. Always better to try to sell your vehicle to a private person as it will fetch the best price. Car dealers will only give you a rock bottom offer as they have to clean, inspect, and resell with warranty + their commission.