Thanks for the replies guys, I appreciate it.
According to the place that did the tints for me, the shade is similar to what manufacturers refer to as "Privacy Glass". When I bought ine, the dealer already had the car in stock so I didn't get the chance to order it as an option. However I think the job has been done well.
There was 1 shade darker than mine which is the Limo Tint. As for lighter shades I think there were either 2 or 3 shades between the one I had and what the car comes with as standard. Dark smoke I am lead to believe it's called!
It certainly makes a difference in this weather!! As for visibility in the car, it's not as dark as you might think. Just like looking through sunglasses and it's still ok at night.
The sticker under the wiper is from the company that did them which is
www.tintr.co.uk They are in Nottingham.