When I worked in a dealership, they always put the newest, least experienced and youngest mechanic on the lube rack. Needless to say, we did have a few comebacks.
I take my family cars to the dealerships when I get their $29.95
oil change specials. My cars all hold 8 quarts, so this is cheaper than I could do it at home. I always check the
oil level and for leaks when I get the car back, just in case.
I took my hemi jeep to a local service shop that had a $24.95
oil change special. I figured how hard is it to screw up an oil change. I told the writer that the hemi uses 5/20 oil and holds 8 quarts. When I got the car back, he had put 5 quarts of 10/30 oil. The check engine light came on immediately as the cylinder deactivation system won't work with the heavier weight oil. And it was 3 quarts low. Needless to say, he did another oil change and got it right that time.
But, nobody touches the cobra but me!