I'm hot, pissed, and not happy. So bear with me. I spent six hours today installing the new IData Maestro kit, all the adapters, Alpine 5 channel amp, and everything else in my 2020. I'm going to document this because there are problems compared to the earlier year 4Runners - namely, some of this shit doesn't fit. It's been a frustrating day but I'm 85% there and hope to have it completed in a day or two. Not going to entertain comments about why I switched head units. The shortcomings of the OEM head unit have been documented to death.

The first problem is with the USB adapter that everyone has used for late model 4Runners, the Metra AX-TOYUSB. It does not work. Toyota changed the OEM wiring harness to a completely different plug so that the Metra adapter does not work. I can work around that by running a USB cable to an empty dash slot. Here is the '20 OEM plug:





But by far the biggest problem is that the '20 head unit and A/C components have changed so much that the Scosche 2106B dash kit doesn't even come close to working. The first problem is with the hazard lights button, which Toyota has apparently made big changes to:



Scosche dash kit on the left, OEM on the right. As you can see, there is no way the OEM hazard button will fit in there. So you have to drill out the Scosche unit, do the same to the OEM unit to remove the black cover, and hope the OEM unit fits on the Scosche dash kit. But it doesn't, so you have to drill out the holes in the Scosche dash kit for a future plastic weld of the OEM hazard button into the Scosche dash kit. You will also have to modify the dash kit by cutting out the top and sides of the hole for the hazard unit so the OEM setup will fit. See below:



Which brings us to the next problem, the A/C vent thumb wheel covers. The OEM ones do not even come close to fitting the Scosche kit. At all. You will have to drill out the Scosche dash unit holes to make them bigger, cut various parts off the OEM covers, and reshape the bottom so that they will fit. And then there's the matter of reattaching them to the Scosche kit with plastic welding (via solder gun) because there is almost nothing there to attach with. I have not figured this out yet.

I got the amp, speaker wires, RCA cables, power/ground wires installed and the amp mounted under the passenger seat. I got the Maestro unit and wiring harness, Sirius tuner, and everything else installed too - then ran into the above problems. So I ordered another Scosche kit (because my wife managed to scratch mine by moving it), tucked all the wires/harnesses away, and reinstalled the OEM head unit.

New dash kit comes in tomorrow and I should finish the installation by Saturday evening, now that I know what needs to be modified. I've not seen anyone do this project on a '20, so I'll keep supplementing this thread with info and pics.