coolant drain plug on 2008 Acura TL

On the Acura TL 3.2L, where is the coolant drain plug that drains the rest of the coolant from around the engine? I only get a little over 4 quarts from the reservoir and the radiator.The total capacity is about 1.73 to 2.0 gals.

Asked by for the 2008 Acura TL
There should be a drain on the block as well but I cannot find its location in my information..
1 more answer
Is on the button of the radiator