The side mirrors, I am sure were simply removed to make the car look cleaner and with smoother lines.
I am just guessing here, but I recall seeing what looked like a camera lens mounted in the lower portion of the rear bumper. (In the lower right triangle area.) as seen in the zoomed in photo below:
More then likely, there is a large screen built in the dash that shows the visual behind the vehicle.
Also, the Senku has a lower rear window much like the MX-3 has only much larger. The driver could use this window to view the rear using the Rear view mirror. I beleive the first generation Honda CRX also had this type of window.

Jeff Aycan - Site & Forum Owner/Administrator
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