Place: South India.
Situation: Parking in an open space with no shade, morning to evening.
Temperature: 30 to 40 degrees Celsius.
I have parked my car under the hot sun for a week, and I noticed there were squeaks whenever I braked, and even the engine sounded different. Even my neighbour says (without me bringing up the topic) he noticed problems with his car after repeatedly parking under the hot sun. I need to convince a person to install some kind of shades in the parking area, but without knowing exactly what is happening to the vehicle, I won't have any convincing points to present to him.
Whether it is a car or a bike, I assume the fuel evaporation would be quicker and all the other lubricating fluids in the vehicle would also be affected. A colleague even tells me her scooter does not start if rainwater enters it (hard to believe though). I also saw this post about headlights coming on spontaneously.
I saw this video about using sun-shades, but they don't say anything about the bonnet. Other websites speak in a general way about 'the fluids', but offer no details. I am posting here because I want to know the specifics.