I have a Walmart story as well, but it's not nearly as bad as Jiffy Lube - the last oil change I did in my 240 DL Volvo before I did them all myself was at the Walmart near me. The tech guy was really new, not ASE certified or anything, and ended up doing the job about five times before he got it right. Nothing actually went wrong with the job, but it took close to an hour, and they tried to charge me for all the additional oil the guy had spilled, and the four oil filters he had ruined before getting the last one right - some BS about how my car "Wasn't up to spec, caused a lot of difficulty." I told them they were lucky I wasn't charging THEM for the mess they made of my engine bay. I actually watched the guy squeeze one filter with a wrench until it broke, and poked a hole in another with a screwdriver trying to see if he had tightened it enough (?!). Man, from then on it was Oil Change City in my driveway...