Curious to know too..based on the price alone can do every 1-2 years interval

I just recently found out that my front windscreen has been without tint for close to 2 years, since I bought it direct from owner, not aware it was removed for puspakom inspection. Which explained why it was so hot on my dashboard until my LCD meter turn blur..went to install tint with spec: irr95, vlt 50 and UV 99 about 2 weeks ago - but until today can't evaluate performance because there is not a single extreme hot day