Today is the first time I used it due to mandatory yearly "car inspection" and I had to fill up with more coolant but there is no sign beneath the car which is strange. Also the heat issue is not an issue anymore I get outside air now when I use the fan. Dont know what that was but its gone now. I believe that if I still have to fill in more coolant and I cant find any leakage I need to check if the oil stick has grayish/light color which will indicate that I have a head gasket(is that correct? I'm swedish so not sure) problem. I sincerely hope not.