This study analyses the regulation of “heterogeneous products”—those incorporating interdisciplinary technologies subject to multiple agencies and regulations. Despite recognising the need for coordinated regulatory approaches, no systematic frameworks exist. We developed a framework to analyse both heterogeneous product composition and corresponding regulatory design, exploring their interrelationships. Applying this to case studies of vertical takeoff and landing and roadable aircraft, we found that regulatory interpretations of similar product characteristics varied, leading to differing regulatory responses. Our findings demonstrate a strong link between product classification and applicable regulations, highlighting the importance of considering both concurrently when designing new products or regulations.