Hi, nano series is a solar + security film so it's good to apply on side windows. Both crystalline and nano have same spec reading and the different is only the thickness. But nano series is only available in nano 40 and nano 70, so apply nano 40 will no pass jpj and nano 70 will be too bright for side windows. The darkest allow by jpj is 50 so crystalline 50 is the best heat reject film and compliance with jpj.

If you worry about safety, you can always add the 4mil 3m scotchshield security film (clear type) on top of the crystalline crystalline 50.

Hope it's help.