Vinegar is 5% acetic acid and is an irritant to eyes, skin, and respiratory system. Apple cider and some other vinegars leave a residue when it evaporates, hence the reason for limiting the time on the car as well as your exposure to the fumes. And the vinegar does the cleaning job within a few seconds. The same rules apply to alcohol, particularly if you've diluted it with tap water (residue). The problem is more the residue left after evaporation than any potential for damage from either vinegar or diluted rubbing alcohol.