this is what i heard from a friend of mine working at 3M tropicana there...

he used to use 3M tint on his vios (employee can get better pricing)

after a few years, he changed to huper. I asked him why he changed cause i was also thinking to get 3M for myvi and my friend told me that 3M tint will shrink (especially the front windscreen)

I am here not to flame or endorse any product, just stating what my friend experienced...