Cooperative mobility is emerging as a key technology to improve energy efficiency, safety, and road capacity while preserving a high degree of individual freedom. This has attracted a large interest by industry and academia, largely focused on vehicle safety applications, but also on fuel savings by enforcing smoother traffic conditions. More recently, the potentially high benefits in terms of fuel efficiency also for the single traffic participants have been addressed. However, production maturity and public acceptance of cooperative mobility can only be achieved if safety, energy efficiency improvements and compatibility with other traffic participants is demonstrated in a convincing way. Traditionally, similar aims have been tackled using large fleet tests. In the case of cooperative automated driving, the number of use-cases and participants makes this procedure prohibitively expensive. This paper proposes an integrated approach in which a physical engine test bench, a high fidelity vehicle simulator working online and a large scale traffic simulator are connected to provide a representative and fast testing setup able to replace large fleet testing.