State limit is what most dealers tint to, but I'd be surprised if they tinted the rear privacy glass as well. Mine certainly didn't. In TX the factory privacy glass is about 2-3% darker than the state limit which is also 25% here.
This is true and 25% is pretty dark to see out of. I wouldn’t go more than 30%, if that.I don't think I would want the rear windows any darker. Every time my kids use the sun shade on the siding door windows, it makes it SO much harder to check my blind spot.