Time for a rant from the other side: I work at a dealership. I worked at independents for 22 years before that. I like having the parts fit perfectly every time now. I dislike the corporate mentality.
Where I work, scheduled maintenance - oil & filter, clean/adjust brakes, rotate tires, load test battery, fill the fluids, give it the once-over, is about $10 more than Jiffy Lube charges - and they don't pull the wheels off. Hardly overpriced. AND we have records of it and all other dealers can access it, too. You bought a battery and it dies 8 months later in another state - no problem. No hunting for receipts, no hauling it to the store, easy.
Here's a scenario: car stalls in the morning. I find a lot of sludge in the throttle body. Is it too much? We could try cleaning it and see if it stalls the next morning. But the customer won't leave it overnight for us - the work order says promise time is 5:00 MUST. I could clean it and ask them to try it. Or I can sell an idle speed motor and know it's fixed. Here's what happens: I try to save them some cash. Problem is still there, car comes back. Suddenly it's a "recheck" and shop foreman gets involved, royal pain in the rear. Then they get a postcard survey. Question one: was it fixed right the first time. No. No matter how much we explained the scenario, they still see it as no. So I get dinged and my Customer Satisfaction Index drops. Sometimes a lot, when only four people out of literally hundreds I work on reply. No quarterly bonus for me. Gotta score 90% or better... Next time, it's CYA.
Here's another: guy takes his car to some quick lube, only comes to the dealer for warranty. Comes in with a really annoying rattle, idling in gear. After much searching, noise is pinpointed. The air filter they sold him is too thin, and the air cleaner lid doesn't clamp tight, so it rattles. Not warranty - nothing the factory did wrong. We tell him what it is. He won't even buy the right air filter from us!! And since the initial estimate was zero, as it appeared to be warranty, he drives off for free. Leaving the mechanic to try to get paid on an in-house basis.
A recent one: car failed Smog Check - horribly. Amazing the car wasn't blowing black smoke. Someone else sold the guy a carburetor, a catalytic converter, and an oxygen sensor to no avail. And it probably exceeded the blue book value of the car. I spent about an hour and a half straightening out scrambled vacuum hoses, and running a few checks and found the wire for the feedback control was cut. Looks like it had gotten pinched in the air cleaner. Go root through the wiring connector junk box, snip,snip, crimp, crimp, cured. I'd be willing to bet there was nothing wrong with the carburetor. The oxygen sensor could have been bad - it was 20 years and 180,000 miles old. The catalytic converter, almost certainly bad, but only from running grossly rich for who knows how long. 1/10 the cost, and fixed.
How 'bout those tire pressure sensors? Some yahoo at a tire store doesn't know they exist, and breaks it off patching a tire. Then the customer comes in with a warranty complaint. Nope. That'll be $115 for the sensor and $100 to reprogram the system. Unless the tire shop has the $9000 laptop with the proprietary software. Or the junior version - a $400 cable, you provide the laptop, and $2000/yr subscription for the software. But the dealer has to have all that stuff. That's part of why our labor rate is higher. You sure saved big, there, buddy. We charge $15 to patch a tire, and the tire place is only $12. And if we break the sensor, we fix it and reprogram it for free, right then, and you're none the wiser.
One independent I worked at for literally weeks charged MORE than the dealer hourly rate. People assumed he was cheaper because it was an independent!
I've seen so many hack jobs. We tell someone they need a battery as part of their service. They say no. Next time we see them, it's for some complaint that we find was caused by their new, loose battery careening around smashing electrical connectors. Because to save the $20 installation and another $10 on the battery, they went somewhere else. And since somewhere else didn't have the right battery in stock, they stuck something else in, and the holddown wouldn't fit. And now the customer gets to pay for a bigger repair.
I could go on and on and on, but dinner's ready.