In the last few years numerous connected vehicular applications and services have been developed. Most of them reside in the infotainment domain, but safety-critical use cases are within the scope of current realizations. As the performance of the wireless link has a major influence on the applications' reliability and functionality, it is important to consider its characteristics as early as possible during the development process. In the prototyping stage network simulators are powerful tools. Dedicated scenarios can be arranged and repeated as often as needed in a reproducible way. To improve the validity of the simulation results, the wireless link has to be modeled as realistically as possible, considering in particular the data traffic of concurrently active users. By focusing on High Speed Downlink Packet Access (HSDPA) we present a novel traffic generator, which is realized in the NodeB's scheduler. The traffic generator places additional User Equipments (UE) inside the scheduling process, which produce the desired network load. The number of additional UEs is derived from large sets of in-field client-side throughput measurements producing simulation results, which are very close to reality. The new approach is presented spanning from the modeling of traffic to the final implementation and validation using the network simulator ns-2.