just got my oil changed at firestone because i dont have ramps or a jack low enough to get under the car. drove it all night (about 40 miles) and then started it up the next day (sunday) and it was whinning really loud, popped the hood, could hear a knocking from pass side of engine, and ticking from right side, along with the whining. no oil on dipstick, started it up after today and it wasnt really knocking or ticking as bad but still whining just not as loud, also no oil on dipstick. they should be at my house any minute to take a look at it. just thought id post this and see if theres any precautions i should take in case they did forget to put oil in it and theres damage to my motor. i really dont know how i could prove that i didnt empty it or something.