You let me down, Mex Muffler!!!
I was all ready to give a great review for MM. Their oil changes are dirt cheap and they fixed my loud muffler. Muffle repair+oil change was less than $100.
At my last oil change, however, they did not tighten the drain cap enough, and as a result, all my oil leaked out.
I returned to MM with my complaint and they will contact their Chicago office to possibly write me a check as a refund for the oil change (I don't know if that will actually happen, or when).
I've heard of these kinds of errors at oil change places before, but I didn't think it'd happen to me. I don't know if it's more or less likely to occur at a different oil change place, but I am wary of MM now.