I used to go out of the way to help a customer, but after they all started selectively listening to my advice and screwing crap up, I've given up. They get their parts and good customer service, but I don't go out of the way for anyone anymore. Especially with all the ungrateful fucks. Next time they usually expect you to do the same thing, and I just don't have time to do that anymore.
For example:
We have a $700 Autometer tool to test batteries, starters, and alternators on the car. It's pretty cool. However, if a battery fails a load test, it won't run a starter/alternator test. Pretty stupid if you ask me.
Customer comes in, battery lights on. Grab a voltmeter because they can't pass a load test. 12.2V. I told them there alternator wasn't charging and that they were likely going to replace the alternator. HOWEVER (this is the part they didn't want to listen to) they needed to take it to a shop to verify that, since some cars have a fused charging system, and there are other possible causes.
They came back 3 days later raising hell and making all kinds of threats because they have the shop install an alternator, and 'it ended up being the battery.' Right. Autozone gives 'em a free battery and tells them to kick rocks.
Retail sucks. But hell, it's a job and it pays money.