Since you're outside of the US you may not know that the blue Chevy air-conditioned decal was from the 1960s, when automobile A/C was really rare and expensive relative to the overall cost of the car.My ol' '96 Toyota estate had a "COOL" edition sticker on the rear window...
Yep, AC, 4 speaker audio system with CD-changer were not common back then...
I remember a neighbor having a Chevy station wagon with A/C in that era, with that same sticker on the window. The reason I remember it was it was the 10-passenger version that had two 3-across seats and two 2-across seats in the far rear of the car. They'd stick us kids in those 4 back seats, roll up the windows, turn on the A/C and it wasn't powerful enough to get to the far back of the car and we'd roast our butts off. Eventually we screamed to the adults that we were dying back there and they had to open the windows.