No 'edge gap' window sunfilms that cops can't detect. Do they work?

I recently came across a technique of shaving/filing full-window films, i.e. applying the film to the entire surface of the window without any gaps and then filing away the top few millimetres.

BHPian iamitp recently shared this with other enthusiasts.

As many BHPians would have experienced, the classic traffic cop sun film check is to roll down the windows and look for that telltale gap at the top, in the portion that slides into side window frame when fully rolled up.

I was told by my installer that this is inevitable as that 1-2 cm needs to go into the frame, and any film would come off.  I think this must have been standard practice, because cops have evolved to specifically check for this.

However, I recently came across a technique of shaving/filing full-window films, i.e. applying the film to the entire surface of the window without any gaps and then filing away the top few millimetres to get an almost factory-tinted installation without any telltale gaps. The technique is illustrated in a video, and seems to be from the US.

If this indeed works, then it could be a game-changer for all sunfilm installations, as it would be nearly impossible to tell apart a sun film which meets the factory-tint norms.

Thoughts, please.

Here's what BHPian Ferruccio had to say on the matter:

Umm... how would the said tinted glass react to a cigarette lighter? A factory tint would be unaffected, a film would shrivel up and thus give up the ghost. Perhaps I am wrong, but that would be a simple way for the cops to still separate the two.

Here's what BHPian shankar.balan had to say on the matter:

Will anyone here even allow a cop brandishing his cigarette lighter anywhere near our cars? I, for one, would most certainly protest. There is a practice here in Bangalore at certain spots in the city where the cops lurk in wait and especially target cars registered in other states. I experienced this in early 2020 on a Sunday when driving with my parents in their car (they were visiting us) when we got stopped and the cop did the fingernail-on-the-window-edge-test, but to no avail.

Here's what BHPian deetee had to say on the matter:

Why go through all this circus to look cool, can't we get to replace stock glass windows with tinted glass windows ?? All kinds of mods exist for cars, but I have not come across any posts where people replaced stock window glass. I think replacing stock glass with tinted glass will not be more than 30k that is required for fancy tints, like the other gentleman was flaunting in another thread.

Here's what BHPian Raghu_M had to say on the matter:

Am sure the cops have their ears to the ground. Your thread will catch their attention soon too. They will devise a hack to find out if there is a film indeed. As long as there is a law against installation of sun films, they will continue to do their job (rather aggressively) to churn out those challans and generate revenue to the dept/govt.

Here's what BHPian RedTerrano had to say on the matter:

This "hack" works on the premise that the authorities undertake scientific measures to detect the presence of sun films.

In India, cops are so advanced, that they can summarise visual light transmission to be below prescribed limits just by looking at it. Similarly, they can figure out the speed too without any speed guns. I have personally experienced this. The former in Chennai and the latter in Bangalore.

Not worth the trouble in my opinion. Also it's illegal.

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