Very true. In CA, I know of many that were optional for the slightly lager rectangular mirror and YES, w/ extention rod w/ lock screw. As for the commercial chassis, lots of that add ons were left to the end builder, but a few were special ordered w/ factory optional morrirs and lights amung other items. It was not uncommon to find factory ordered 5" round for driver and medium square for passenger side w/ exra reach arm.
