Things I've learned:
the most difficult part of a car to repair is the power antenna (mine moves up and down now but still no signal and I can't get the nut/cover thingy on)
The 7550 harness is basically the same as the 7551 just with 2 RCA jacks on it
The Bose system does not need a LOC (no static) and will take already amplified signals just fine
The mirror link on Chinese headunits is better than the one on brand name ones because it will mirror the entire phone
The 7417 dash kit is not compatible with the Bose system unlike what the Bose replacement thread says
You may need to drill new holes into the frame if your new headunit is 0.5mm too wide (you will also need longer bolts)
You may need to tie in the amp/antenna on into the accessory power depending on what the headunit does to turn them on.
Using a video cable with a power lead makes giving a reverse signal easier.


I have absolutely horrible alternator whine now though so I need to figure that out. I have all 3 grounds going into the stereo subframe. If the car was manual I would be able to shift it just from the whine.
Also the coolant leak needs to be sorted.. and I think the IACV and TB need a cleaning. And the front fenders need a little "deleting a driver that hits the same part of the garage in different ways drive the car" the whole airbag light thing too.. (open both front doors, turn the car to on, within 7 seconds press driver side door trigger 5 times, turn car off and remove key)