Why film over privacy glass ends up darker than you expect
Factory privacy glass is tinted in the glass itself, and film is a second layer on the inside. Each layer lets through a share of the light that reaches it, so the shares multiply: glass at 20% and film at 20% leaves about 4%. A shade sample held against clear glass doesn't show this, so on an SUV with privacy glass it can mislead you about the finished look.
The film numbers in this calculator come from LLumar's performance data sheet, which measures each shade on clear 6 mm glass. That's why the result is an estimate. The reading on your actual window, with the film on, is the number that counts. The answer on tinting over factory tint covers the practical side.
Matching the front doors to privacy glass behind them
On most SUVs, vans and pickups, the rear glass is dark from the factory and the front doors are clear. That two-tone look is why people ask about the front doors. In BC, MVAR s. 7.05(8) allows no film on the front side windows, so there's no legal way to match them. Behind the driver, any combined darkness is legal on a vehicle with mirrors on both sides. The tint law checker covers each window.
Picking a shade with the result
Three things to weigh once you see the number:
- Night vision. At the darkest combinations, reversing in an unlit lot gets hard. The night driving answer goes through it.
- Heat. Darkness and heat rejection aren't the same thing. A light IRX shade over privacy glass rejects more of the sun's energy than a dark dyed one; the heat rejection comparison has the numbers.
- Privacy. Privacy comes from the contrast between a bright outside and a dim inside, so a moderate combined number often does the job.
Getting it measured
If you'd rather not guess, bring the car to the shop on the Langley Bypass and ask before you choose. SUV rear-glass tint starts at $260 and a sedan or pickup at $240, in LLumar ATC, with IRX and AIR quoted as upgrades. The SUV tint page covers the seven-window rear package.