Virtual methods in vehicle development, such as driving simulators, require real-time capable multibody models that accurately reproduce the driving dynamics of vehicles. The wheel suspension is a central subsystem that influences driving dynamics not only through its kinematics but also through its elastokinematics, which arise from elastic bushings and the flexibility of the suspension bodies. Detailed multibody models of wheel suspensions therefore encompass both slow and fast dynamics components. This paper presents a modification of a linear-implicit integration method for quasistatic approximation of selected coordinates associated with the fast dynamics range, separating them from the actual time integration. Within a double wishbone suspension model featuring flexible bodies, selected high-frequency flexible modes are quasistatically approximated. As a result, computation times are significantly reduced, and the accuracy of real-time simulations are improved.