Here's a recent thread about it but there are others if you search on there:
http://my350z.com/forum/exterior-and-in ... ightz.html
Seems a bit hit and miss and some people don't find the cracks until the eyelids are removed. Obviously the usual my350z pinch of salt applies too! Personally I wouldn't risk it though, especially if I had the 06+ headlights as they are £700+ second hand and the lenses aren't available separately.
EDIT: There is some mention of "overlays" in that thread too, not sure if that is the same as the tinting film though.
Good find Matt, can't for the life of me fathom how tinting the lenses slightly or fitting eyelids can cause the lenses to crack though........ someone please explain the science bit to me