The factory system is not bad for an entry level car. Really where it lacks is playing it at a high volume, it tends to distort but I highly recommend not playing it at that level. The biggest change you can make to any factory audio system is to add a subwoofer. You will either need another amp and have to mount it somewhere in the trunk or you can get this adapter that allows you to get a small form factor amp, some can still push 600W, and put the amp in the same factory location. Kicker and Sound Ordnance both have great small form factor amps that can fit in the factory location.
The dimensions in the file name are for the holes.
Factory amp uses speaker level inputs just as an FYI. So you will need a converter to RCA, replace the headunit, or get an amp with speaker level inputs.
I have an Android Headunit but I honestly don't think its really anymore worth it over just getting a headunit with Android Auto and/or Apple Car Play.
No bump unless your unit is taller than mine (2 -1/16" or 52.4mm)
Full access to the tuning
Uses factory mounting points although you only use 2 of the 3 nuts
I used one of the pop clip holes in the side panel as my ground point, had to sand it down to get proper grounding
Made using Polmaker ASA filament