Thanks for the reply
@Lovemyev .
I thought I'd test the front glass as you suggested so here's the result below.
There's definitely a slight tint in the glass but minimal and not shown that well in the photo.
As
@Fishettibean mentioned before, unless you want to spend cash on a proper light testing kit, the percentage is debatable but hopefully the clearest tint that GT do keeps the fronts legal and still gives the UV/Heat protection that I'm after.
The local company that quoted me said for the tiny rear quarter-lights they remove the inner white trim panels to get a cleaner finish, at the risk of potential squeaks and rattles though..?
I'll be having a word with my own insurers beforehand but hopefully no problem there