Check on the engine side of the radiator, one of the two lower corners. It can be hard to see and get at. Mine was a small plastic flat blade, sort of like a key.
Look at the lower or rear of radiator
the sunfire auto trans has no drain plug. You must drop the pan.
the rad drain plug is located on the drivers side behind the front bumper
It's located on the engine side of the radiator. Lower passenger side. You have to get under the car to access it though. You can't see it from the top.
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If it does not have a drain plug, just simply remove the lower radiator hose.
The OBD2 plug for most GM vehicles is to the left or right of the steering column, at the bottom of the dashboard.
It sould just pop off like a plug in a wine bottle.
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on the radiator
The 1991 Pontiac Grand Am radiator drain plug can be found on the bottom of the radiator. The radiator drain plug will be in the center of the radiator bottom.
The very bottom of the engine. Plug is at rear.