Some vehicles of the game have this bug. I've made a list of those concerned.

SUV : right mirror disp. left picture
Zamak ammo & repair : don't display anything (both indep. and opfor)
truck, truck boxer and fuel truck : right bottom mirror seem to display the left rear of the vehicle instead of right rear.
ifrit's mirror's are... yes... useless.
Tempest device, transport, ammo, fuel, repair : left mirror display right mirror picture.
hunter (all versions) : left and right mirrors which are the closer from the driver : display an inverted picture (objects on the left appears on the right and vice versa)
all HEMTT versions : display the same picture, the rear of the truck instead of the right or the left (maybe made on purpose)