The proliferation of vehicular ad hoc networks necessitates efficient data transfer protocols, particularly in the context of Cellular Vehicle-to-Everything (C-V2X) communications. This paper focuses on enhancing the performance of the Quick UDP Internet Connections (QUIC) protocol, focusing on cooperative vehicular networks supported by aerial drone relays. While QUIC outperforms traditional protocols, its default congestion and flow control mechanisms do not adequately address the unique challenges posed by volatile networks spanning the terrestrial and aerial domains, as they are characterized by frequent topology changes, and high propagation delay volatility. We analyse QUIC's congestion and flow control and propose enhancements to optimize its performance in such networks, specifically designed for C-V2X communications in Open Radio Access Networks (O-RAN). Our proposal adjusts connections' congestion window size and individual streams' flow control windows in a channel-aware manner. Simulation experiments assess the performance of our proposal, comparing it with QUIC's default mechanisms. Our proposal can be seamlessly integrated into existing implementations, making it a viable approach for improving performance and addressing the challenges specific to vehicle-to-drone communications. By addressing QUIC's limitations and optimizing its performance for C-V2X applications in O-RAN, our enhancement offers a valuable contribution towards enabling low-latency, and resource-aware vehicular communications for the realization of autonomous driving and advanced vehicular services.