This is dope i love it! just got a new 2015 es350 with 60k on it and want to do a 10" sub and speaker replacement. nice job i bet it sounds good

 

Hey Ratchey, sorry, I know this is an old thread, but I had a question about when you routed the power wire through the firewall. I was going through a grommet on the passenger side footwell. All is good going from the engine bay, but it feels like there is another grommet on the passenger cabin side. I can only feel it and definitely isn't a line of sight to the grommet. Did you remove the lower passenger side dash, air bag, etc to get to that area? Or just force it through by touch?

 

The best/easiest location I found was slightly under the steering shaft where it goes through the firewall. There's an elongated rubber grommet than extends down a couple inches or more away from the assembly. You'll have to pull the carpet and insulation away a few inches from the inside to get that low. Poke or bore a small hole through it (smaller than your wiring) then carefully feed your wire through it.

 

I know this is way to late but never got notified of this post. I totaled the car in 2018 and moved to a GS for about a year and now an LX so haven't been here is quite a while.
I used harness H88 which I believe is the output harness. I cut the wires I needed, ran from the stock amp to the DSP, to the aftermarket amp then back to the same wires I cut just on the speaker side. I don't remember what was on the signal side. I know the ML system uses a MOST connection which is not easy to adapt to DSPs or amps. I believe the ES had 2 digital inputs which I didn't want to mess with.
Again, sorry this so late and probably useless now.

 

I know this is way to late but never got notified of this post. I totaled the car in 2018 and moved to a GS for about a year and now an LX so haven't been here is quite a while.
I really don't remember but I almost always go through a grommet on the drivers side then route the direction opposite of the signal cables.
Very sorry. I know this is too late and useless info now but it looks like someone else was able to answer your question.