Hunting down a parasitic draw, is this the right way to do it?

[BoxsterInTheSun]

The battery on my 2002 base 986 goes dead in around 5 days if it isn't driven.

I suspect it might be something to do with the double din radio I installed, although can't be sure as I did that install having not owned the car long enough to know if I caused the problem or not.

This morning I attempted to test for a parasitic draw, but I'm not sure if I have the multimeter set up right? I've included a picture below in the hopes someone can give me a bit of guidance.

My understanding is anything over 50 is not good, and mine is reading around 113.

If this setup is correct, my next step would be to start pulling fuses until I find the one that drops the number back down to something around 50.

Is that the right way to think about this?

Thanks in advance!