Mechanics
Body shops
Car salesmen
Tire shops
Car audio guys
Anything that has to do with cars

Almost every encounter with them is based on them not being fully honest or trying to upsell or outright scam you

Go for just an oil change...they find half a dozen things that need repair

Go to get 1 tire replaced...your other 3 tires need replacing asap...and they just happen to have a special deal going on that day

You basically go into any encounter with them on heightened alert not to be screwed over

perhaps because it's one of the easier ways to scam so scammers gravitate toward it...most people don't really know much about finance or anything about how modern cars run/whats wrong with them/how to fix them.

dentists are the worst. i go to a new dentist every year, and they give me a different opinion every time.

last year the dentist said a tooth in the bottom left of my mouth needs a filling done. i was skeptical so i held off on doing it.

this year i saw a new dentist who didn't even mention the tooth from before - they told me a tooth in the top right of my mouth needs a filling done.

i bet the majority of fillings are not necessary. many cavities can heal on their own if you improve your diet and dental hygiene, but there is no money in that so dentists will pressure you to do fillings.

it's the worst because dental procedures permanently alter the structure of your teeth. once a filling is done, that part of the tooth is gone forever. and fillings need to be replaced eventually, which further gives dentists more money.

Never had an issue with my Toyota and Subaru car salesman brah.