you know how dark shirts absorb the sun heat well its practically the same just with material.
"Why is the inside of a car so hot after sitting in the sun?
Cars warm up in the sun due to the greenhouse effect: Sunlight passing through the windows into the car is mostly absorbed by interior surfaces, then radiated back to the air as heat. ... “As a consequence, the inside of the car will warm because radiation is coming in but not much is going back out.”Jul 27, 2009
Curiosities: Does a dark-colored car heat up more in the sun than a ..."
^^ Also is caused by something called the Greenhouse effect which causes ultra violet rays to come in and be reflected with infrared rays which get trapped and therefore cause heat for the car to be hot since infrared radiation is another word for heat
