Passing with oncoming traffic

i was told by my instructor ( mind you this is 1977) that in a situation like this always allow space for a car door to open , so rule of thumb would be if you can pass the parked cars plus allowing extra room for an open door go for it, if you’re having to leave a ■■■ papers width to go by , dont. what you do after the test is up to you . i’m usually trying to get out of my car whilst staring at a super single about 6 inches away.