I am a quick lube manager and have been working for the same place for nearly six years. We are brutally honest about customer's vehicles and are very fanatical about procedures.
Every drain and check plug is torqued to factory specs. Why? Because several manufacturers use aluminum oil pans such as Chrysler and Hyundai. If it's overtightened one too many times they threads easily strip. If a plug doesn't clean up through the straightener, I suggest replacing it.
Air filters are checked every 20K to 30K miles and suggested to be replaced if light won't pass through. If wiper blades are torn or streak, I suggest replacing them.
Oil grades and tire pressures are usually done to factory specs unless the customer has a preference.
We do carry "snake oils" like Slick 50 but they are not "pushed" on customers, as is anything else. Many brought thier own so we now carry it. That wasn't my idea though..
We also have a service department so if repairs appear to be needed, such as a torn CV boot or tires or etc. We reccomend checking with the service department.
The bad part is that untrustworthy businesses tarnish the reputation for all. Very often a car needs several items but customers refuse an air filter and wipers because they are "overpriced" ($1 more than Wal-Mart). They don't want a drain plug because we're 'conning' them. It makes me disgusted sometimes.
But I wanted everyone to know that a quick lube isn't always a bad place to go. Keep in mind, we're car people too!