I recently tinted the top of my windscreen on my second van, too,  and
it makes a significant difference.  We live in an East<>West river gorge
and I often find myself driving west into the setting sun. The dark tint I
used helps with that.   It also keeps some of the sun off the front inside
of the van, including the passengers..   A nice enhancement for more
comfortable driving at little expense.  I used tinting film from one of the
chain auto parts stores..