Hey Toadie,
I have installed the 3M film, and tried leaving the car out in the
sun for 1 hour.. (i didn't have a choice anyway!). I still feel the
heat, but later, i realised that it is because in front, in the
driver's seat, the front film of course has lesser IR reduction
compared to the back, which was much cooler.
But, it is definitely better, as the heat dissipated much faster
then before, after the engine & aircon is switched on! So, all
in all, quite happy with it and the customised mats.
48 hours after installation, the rear window film makes everything
looks distorted, so i had to drive carefully (cars behind me looked
like many lambourghinis & ferraris!!), but, now, it is fine,
though the demister lines are now more prominent then before..