With the increasing complexity of electronic vehicle systems, one particular “gap” between function development and ECU integration becomes more and more apparent, and critical; albeit not new. The core of the problem is: as more functions are integrated and share the same E/E resources, they increasingly mutually influence and disturb each other in terms of memory, peripherals, and also timing and performance. This has two consequences: The amount of timing-related errors increases (because of the disturbance) and it becomes more difficult to find root causes of timing errors (because of the mutual influences). This calls for more systematic methods to deal with timing requirements in general and their transformation from function timing requirements to software architecture timing requirements in particular. In this paper, we summarize our shared findings from a strategic corporate process enhancement project “PETRA” at Volkswagen and Audi on this topic, and present lessons learned and a key enhancement step.