My thoughts on less than 50% VLT film on the side windows -
I had 35% VLT (3M RE35) and yes, I was enjoying the lack of proper enforcement. To the extent that I and others like I contributed to the PIL happening in the first place, I stand guilty.
With that out of the way, here are my observations on 35% VLT and lesser films.
I always drive with windows rolled up and the AC on. This is not because I can't bear the heat even during January or anything, but just because I want a quiet, dust-free environment inside my car while I'm driving.
35% VLT
With RE35, the only times I genuinely felt the visibility out of the windows was low was on dark *and* rainy/foggy nights. I drove the car around for a good 6 months (Aug. '10 to Feb. '11, with monsoon '10 being especially torrid in Hyd) and I know for a fact that the RE35 made matters worse during monsoon '11, which was much lighter in intensity.
At all other times, visibility into/out of the car was brilliant. I would never have done something inside the car which I wouldn't have done outside of it. If someone came close enough, they could *clearly* see inside the car despite the reflective nature of the RE series.
20% VLT
Dad's Indigo has a 3M film which is darker than the RE35 but still light enough that I can clearly see out even during night (when it doesn't rain of course). So I'm assuming it's CS20 or SP20 or whatever consumer-grade 20% VLT 3M film was on sale in May 2006.
This film's not so dark that I can't see into other cars, and once again, to someone who's reasonably close to the car, visibility into the car during day time isn't too heavily compromised. To the extent that the CMVR is meant for visibility from the inside looking out and not the other way round, this is bearable.
Once again, just like with RE35, I never felt much discomfort except on really dark and rainy nights. Maybe I was just lucky.
5-10% VLT
Another family member's i10 had extremely dark film (he tore it off sometime in the middle of last year, finally). This was some cheap brand installed by Hyundai much against his wishes. He asked for lighter varieties and they either didn't have one in the 35-50% VLT range or were not prepared to give it away for free/cheap. Under pressure from family (some film *had* to be put), there was no option but to get this installed at the time of delivery.
This film was much darker than the one on Dad's Indigo. It must've been 5 or 10% VLT, not more. Now this was a fearsome experience even during broad daylight. I would simply not be able to make out what's outside. VLR (VL reflected) was also obviously high and not only did this film give me tunnel vision while driving, but also distracted me with vivid reflections of the beige dashboard in my periphery. Visibility from the outside in was even worse - practically nil unless you have your face to the glass. This film is ideal for changing trousers inside the car etc.
In summary, I would think - at least for me, personally - that 50% VLT would be the most ideal on the sides because 35% VLT was great except for one special case which 50%+ could perhaps easily handle. Now, given that even 20% and 35% VLT itself didn't exactly allow privacy (not that I was looking for it), obviously 50% won't. The CMVR pertaining to visibility is pretty well thought-out, I think. In my experience at least, privacy and safe driving DO NOT go hand-in-hand.
The only way out of this is I guess to allow films with VLT of any % *only* on the two rear side windows and not on the driver's and co-driver's side windows and rear windscreen. I think this is a workable solution for those looking for privacy for their families. While I wasn't after films for privacy, I can empathize with those looking for privacy on the road - everyone has their reasons. Of course, sole women drivers will not be covered with this work-around.
Other than to ensure good visibility while glancing over and back to cover blind spots, I fail to see why the CMVR can't be amended to allow < 50% VLT on the two side windows on the rear.
In hindsight, I now feel I should've invested in CR50 instead of RE35. The heat rejection properties are similar and UV rejection is better. It was the cost at which I balked. But from what I see, CR50 is going undetected, and it's possible that I may have benefited from that on May 4.
Regards,
spadix