Definately go for it. Even if you get a 5% tint, it will still keep out a good percentage of UV.

Mine came with it (from FL)

Not sure what percentages it has, but the back is pretty dark. It helps in the summer!

__________________
Dan
2005 E320 CDI - 246k
1987 300SDL TD05-16g, Herlevi pump, Elbe manifold, 2.47 LSD - 213k
Past: 1987 300D - 264k