The development of an automotive system involves the integration of many real-time software functionalities, and it is of utmost importance to guarantee strict timing requirements. However, the recent trend towards multi-core architectures poses significant challenges for the timely transfer of signals between processor cores so as to not violate data consistency. We have studied and adapted an existing buffering mechanism to work specifically for statically scheduled time-triggered systems, called static buffering protocol. We developed further buffering optimisation algorithms and heuristics, to reduce the memory consumption, processor utilisation, and end-to-end response times of time-triggered AUTOSAR designs on multi-core platforms. Our contributions are important because they enable deterministic time-triggered implementations to become competitive alternatives to their inherently non-deterministic event-triggered counterparts. We have prototyped a selection of optimisations in an industrial tool and evaluated them on realistic industrial automotive benchmarks.