They have a Nissan, and it was making a funny noise. She took it in, and the dealer called back, asking over $700 to change the cooling fan - this on a two-year-old car. Money was tight for their family at the time, and $500 would have hurt. I quickly found the exact OEM part at RockAuto for $124.95. Then I called them back, and quoted them that price, telling them I could see in the manual that this is two bolts and a electrical connector, something I could handle with the Leatherman tool and screwdriver I carry every day. I told them that two years was ridiculous for electric fans, as the ones on my 15-year-old Scion are still running swell. And that there was nothing dangerous about electric fans making a little noise, as they had strongly informed my daughter to frighten her. I then said I was coming to get the car that minute, and if did, it would be the last Nissan my family, friends, associates or maybe even you guys here ever bought.

The service writer asked if I could hold, and came back a minute later, saying they would fix the car. For free. Afterwards, we changed dealers, and told the new dealer why.

Never let yourself be bullied or frightened into an instant answer. That's what some of the unscrupulous want. There was a great old show on the old NPR Car Talk that discussed which noises are serious and need instant attention, and which are a minor irritation that you can safely ignore (for a while... In my experience, all sounds mean something). Generally speaking, squeaks and rattles are usually ignorable, squealing and scratching sounds can usually be left for some miles, but heavy clunks, bangs, howling or clattering and heavy scraping sounds when you do something like braking all yell for quick attention.