I've put on the Indulgence Series to my car today from Mr Ong and the most noticeable is for the front window (not the ray barrier series) and i can tell you that it's half the heat generated compared to the standard proton safetint wow, but still got heat la...So i believe the side panel window and the back panel should perform better than the front windshield. I've tested the ray barrier and it's like no heat at all. Still, cannot afford but i'm still soo SATISFIED!!! now need to wait for 3 days to a week befor putting down my window.