Since I moved here, I had been using a particular oil change place. In early December, when I noticed my Oil light would come on around turns (I assumed this would mean that my oil was low), I went in to get my oil changed. I figured that I either had some oil burning in the engine or that I had a leak. I asked the attendant to check to see if there were any obvious leaks. Getting no report back from them when they turned my keys over, I hoped that it was just a minor issue.
I took the car back to the oil change place when the oil light started coming on again. I asked the attendant and he insisted that if it was only on intermittently that it must be an electrical system issue, and that it had nothing to do with the actual oil at all. I took his reassurance and the information to the car dealership the next week.
They listened and immediately decried his theory of an electrical system issue without even looking at the car. They said that if it were burning oil, it would take awhile to figure it all out... but when they put the car up on the lift, they saw immediately that I had a significant leak from two different places. $700+ dollars to fix it (which I still haven't done, six months later). Not only did this oil change place not notice the leak (which had caused oil to drip all the way under the car to the rear axle!), but the dealership said that consistently overfilling the oil probably caused this.
I haven't been back to that oil change facility since (not much cause, anyway, with all the quarts of oil I have to add to the car myself, just to have them leak out over time). Well, I didn't go back until last week.
I needed to get my state inspection renewed. I took the car through a car wash to attempt to eliminate most of the oil on the undercarriage, but there wasn't anything I could do about the "Check Engine" light that was on. I drove up, asked them to check it, and went in to sit and wait (and read a Highlander novel).
Shortly thereafter, they brought me the keys and signed off on my inspection, as I had hoped. They made no mention of any issues with the car, an oil leak, or the check engine light.
It's kind of bittersweet.