what the hell difference does it make how much tint is on the back windows?
shit, in California you could paint back windows and install blinds, for all they care, as long as the front is 35%.
my fronts are 22% and rears are 13%. got pulled over couple of times. not a word about the tints... probably because i put the windows down by the time the cop walked down to my car
however, darker tint in the back, does make front tint look darker.