Hi,

Do you mean it's hot after a long period of time parking under the sun?? Or do you mean it's hot during normal day driving? Which model did you choose? Make sure you verify and avoid any house brand. It's very normal to feel hot if you Park your car under the hot sun for more than 2hour. However, with a good tint, the heat should cool of quickly after you switch on the air cond.

87% heat rejected, you mean the TSER or IR?

If TSER, Don't think any solar film that can apply on automotive can achieve 87%

If IR, it just infrared figure. For heat rejection you need to look at the TSER (total solar energy rejected) for more accurate measurement.

Most shops should have the Infrared meter to test it. You can try to ask the shop that you have tinted your car.