One thing that always made me wonder though is that cars normally have some factory tint already. Like the V60 glass says "MIN 73% VLT" or something which I assume means its pre-tinted to as much as 73%
So 73 and 35 together would make about a 26% (multiplying). That's assuming 73% really is 73ish and not actually like 90. I'd guess Saint-Gobain's QC is pretty good tho.