You are so right
That is been done to me a few times. It seems that most auto mechanics assume that women do not know anything about their cars,even something as how many cylinders it has. I had a 1992 plymouth voyager that had 4 cylinders. When I took it somewhere for an oil change, the mechanic refused to believe me said that it was a 6 cylinder until he opened the hood a saw for himself. I he did not apologize for insulting my intelligence.
When I purchased the vehicle, the first thing that I asked was how many cylinders that was it? I blew an 4 cylinder engine before and was reluctant to buy this one until the salesman reassured me that they were using different kind of aluminum than they did in the past.