Performance metrics & physics
Greenhouse Effect (Cabin)
The cabin greenhouse effect is the rapid temperature rise inside a parked vehicle in sunlight, caused by solar radiation passing through glass and being re-radiated at infrared wavelengths the glass blocks.
A parked car in Singapore noon sun can hit 70 °C cabin temperature within 20 minutes. The mechanism: visible and UV solar radiation passes through the glass, hits interior surfaces, and is re-radiated as longer-wavelength thermal IR — which the glass blocks. Heat in, heat trapped.
Window film breaks this cycle by rejecting the incoming solar radiation before it can heat the interior. A Platinum99-tinted car parked in the same conditions can be 8–14 °C cooler than untinted.
This effect is why "just crack a window" doesn't help much — the dominant heating is radiation, not convection.