While software simulation is a valuable tool for efficiently verifying various driving scenarios, in some cases, linking with actual hardware is essential. HIL (hardware-in-the-loop) simulation provides a higher level of realism and reliability by replacing software ECU models in a SIL environment with actual ECUs. This presentation will introduce a method for enhancing simulation realism using the Xylon HIL system. It will focus on a case study where four virtual cameras mounted on a vehicle driving on a virtual road environment are linked to a real surround-view parking assistance ECU. This ECU requires high-bandwidth video data processing and is a suitable example to demonstrate the benefits of full-speed HIL simulation. We will also address technical challenges that arise when linking physical and virtual domains, such as data throughput, timing synchronization and sensor emulation.