I have not seen anyone open their hood while getting fuel for the last 15-20 years and I am on the road often taking trips from Miami-NYC..That includes New Jersey where pumping your own fuel is illegal and 99% of the customers at those stations never even get out of their vehicle.Every fill-up. Just to check on things .
I generally open the hood about every 4-5K miles to check fluids and clean off dirt in the engine area with a damp bounty towel.
In fact when I ask friends [who have late model vehicles and older vehicles] what grade of oil they are using they give me the baffled look as they have no clue.