Those are shit mechanics who are just trying to steal as much money as they can. I would avoid them and call them out whenever possible. I’ve had some good mechanics who go out of their way to save you time and some who have actually helped without charging extra. Not to say it’s required but the stigma of bad mechanics has ended up being the way it is by having people oblivious to what happens under their car’s hood.
I installed mine during COVID lockdowns - wife got one as a gift for baby shower and we never used it but 2 years later I broke it out during the dark times for toilet paper and it saved our ass, literally. Definitely the best improvement ever, yet some people do feel weird about them, like middle schooler homophobia or some shit