Po Poe

My 8 year old son says to me "cant he just leave the radio plugged in and unplug the factory amp and see if the battery still gets weak"Lol kids think so simply.

Are you sure the parasitic drain is not coming from the stock amp? I saw that once in a 98 maxima when the factory radio was re installed after the installers chopped up the wire harness to put in an after market radio. see if you can get a volt meter on that stock amp power terminal with the car and the D3 turned off see if there is current draw after that unplug the d3 and check it again. You should be able to get the tip of the voltmeter probe into the holes on the stock amp's wiring harness then ground the negative probe.

I've had that same problem in 3 different Gm vehicles that were all either brand new or under a year old and each time it turn out to be a defective o.e.m battery. You should have it tested. Especially if it's one of those Deka ones Gm likes.