I just read these parts, sorry i am not a chemist, but it doesnt sound to me, a layman, that you really want this stuff sprayed on you....
Inhalation
Harmful: possible risk of irreversible effects through inhalation. Vapours may irritate throat/respiratory system. Symptoms following...
And maybe my concept of leaning on a car is different, i could litterally balance ok with the tip of my finger touching your car. Thats all i would need, i am not on about a huge sweaty palm on the roof or any part of the bike going anywhere near the car!
Anyway, i extremely rarely have done...
I genuinely don't see the big deal in leaning a hand on a car at the lights. As I said, if you asked me not to do it, I would of course stop and not think any more about it, unlike our chap today.
Leaning on a car is putting your self in the firing line for Ethanol, Methanol, Sodium Hydroxide, Acid Blue C88, Tetrasodium EDTA (I don't know what half of these are, but its the ingredients list for a popular screenwash)
Good for you.
I use screen wash, do i use it knowing it will spray pedestrians, cyclists, horses? no. I wait until its safer to do so, maybe because i am a considerate driver?