They vary from car to car. Not all makes of the same car will have this problem. But the majority of the discoloration takes place on the outside for most lenses, the inside will have the same problem, but most of the time its not nearly as bad.
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FOR A WOUNDED MAN SHALL SAY TO HIS ASSAILANT
'IF I LIVE, I WILL KILL YOU. IF I DIE, YOU ARE FORGIVEN'
SUCH IS THE RULE OF HONOUR.