The oil drain plug on a 2006 Cadillac STS with a V6 engine is located on the
bottom of the oil pan. The oil pan is the large, somewhat flat, metal part underneath the engine. To be more precise, you'll find it towards the
front of the oil pan, likely on the
driver's side (left side) of the vehicle.
However, getting under the car is necessary to locate it accurately. You'll need to consult a repair manual or an online diagram specific to your 2006 Cadillac STS V6 to get a precise visual. There might be a slightly different placement depending on specific sub-models or options.
