—Car-to-car communication (C2CC) enables cars to exchange information that can be used to, e.g., improve the drivers’ safety or comfort. Recently, WLANs based on the IEEE 802.11 family of standards have been identified as promising communication technology for C2CC. Often, the information exchange between vehicles is of interest for all nearby vehicles so that the communication should be broadcast-based. However, such use cases have not been considered when the IEEE 802.11 systems have been initially designed and a significant scalability problem exists in broadcast scenarios. We present the reasons for this problem and propose several algorithms for dynamic protocol parameter adaptations. Our simulation-based evaluation shows that the suggested enhancements clearly improve the scalability of IEEE 802.11-based systems in vehicular scenarios without changing the main protocol characteristics.