I’ve just passed 1,000 km on my Emira and noticed today, for the first time, a small view through the passenger-side “rear window” when shoulder checking. It was mostly blocked by the passenger seat headrest, so I leaned that headrest back and out of the way, to increase my ability to see traffic in that blind spot. I assume this will depend on many variables, such as the driver height. But if like me, you don’t often have a passenger, perhaps try leaning the passenger seat way back to see if your field of vision improves.