Formula “should” work like this....
Current tint....(.85)x’s New Tint....(35) =‘s (29.75%)
Some shops have 38% tint. But like I said, the way a tint meter works is with calibration glass and is allowed a 3% variance (hence N.C. Law at 32%). BUT it should be calibrated in the same lighting conditions as the test will be in (many officers will do it wrong). The citation would automatically be dismissed if it was removed in 15 days.
As far as inspections, if you get 35% they are going to ask has it been tinted, then you say yes, with 35%. They MIGHT throw a meter on it.
Like I said I’ll throw a meter on mine at work sometime this week and get some more numbers.