The advent of the Internet of Things (IoT) gave us the capability to connect real-world objects to the Internet, making our lives more convenient. However, hackers have been known to crack into these real-world systems causing more inconvenience to the people than making their lives easier. Smart cars are one of the technologies which make our lives easier, but if an attacker exploits its vulnerabilities, they can cause severe discomfort to the passengers and the people around. In recent years, there have been instances where Connected Autonomous Vehicles (CAVs) were attacked by hackers, which granted complete and total control of the car to the attacker, or where the network was jammed, which led to the loss of information. In this paper, we present the simulation of a DDoS attack in a virtual environment of OMNET++ on a network of connected autonomous/smart cars. We also discuss and show how this attack can affect the communication between the cars which are interacting with each other using the well-known IEEE 802.11p DSRC protocol. Related simulation results are presented and discussed.