Base window tint?

I'm wondering about this as well!

I suppose that a good way to find out would be to take an untinted Prius to a place that has a transmissivity meter (or whatever they're called) and test just the bare glass. I think that the general rule of thumb is 70%-80% for most auto glass. But it'd be nice to know so you can get as dark as legally permissible. Here in Texas, they changed the law in 2003 to 25% total transmission... previously was 35% film only.

So if you want to be conservative and say 70% for the glass, then you're looking at 50% for your film to be at 35% right on the nose.

I'm going to start calling around town here (in Austin, TX) and as I'm getting quotes, I'll ask if they can test my bare glass and I'll report back. I'd like to know what the rear bottom window is tinted at too.

Need to buy my Prius first, though... picking it up on SATURDAY. YAY!!! I only had to wait 2 weeks!

 

Glass on my Prius measured 72% before Huper ceramic 50 was installed,
36% after. I had it done last month when I was down in DC. Just makes the car seem so much cooler

 

I just got my side windows done with V-Kool 70 (72% transmissibility of visible light) at Auto Mall Tint Specialist about two weeks ago. They told me that the combination of film and window made it technically illegal (just barely) in California but it was unlikely to be noticed because visually it is a very light tint.

V-Kool is a metal based film so its not good if you have the NAV system. However, I haven't noticed any problems with my cell phone. (Don't have NAV.) What I do notice is that the car is noticably cooler and, after setting in the sun, it doesn't take anywhere near as long for the A/C to bring the temp down. V-Kool has a high IR rejection. It was developed for aircraft and spacecraft windows.

The down side is that V-Kool 70 is not dark so your car doesn't look like something you'd go cruising around in. The upside is that if your wife/partner doesn't like tinted windows they will never know.