We propose a method for managing software assets in the automotive industry to enhance software competitiveness and to reduce development costs. The ownership of software assets in the automotive industry is held by automotive parts companies, making it challenging to exchange these technologies. Moreover, the criteria for determining software assets are often unclear, resulting in difficulties in integrating automotive software and implementing over-the-air updates. To address these issues, we suggest breaking down black-boxed software assets into tradable components, valuating them, and introducing the concept of exchanging software technology assets. Additionally, we provide a structured approach for recycling used software assets and establish a software asset management system for registration and tracking. Our proposed approach can help traditional automotive OEMs narrow the technology gap with automakers such as Tesla and improve their software competitiveness in the automotive industry. This paper contributes to the advancement of software asset management practices in the automotive industry, and provides insights into the integration of automotive software and over-the-air updates.