I’ve fitted a couple now, 1 to a Honda Accord fitted into the factory sat nav screen and one in my van to a Pioneer double DIN touch screen radio. Both just composite video. I think all the touch screen stereos support rear view cameras, auto switching when you select reverse.
Honda did a full set of instructions telling you step by step what trim to remove etc. Invest in some trim removal tools and take your time as you go. Use grommets and protect cables as they pass through the bodywork + panels. You don’t want to have to go back and repair anything! No drilling required both times. Nowhere near as scary as drilling the bumpers for sensors :) Honda wanted £300 for the kit, I think my camera was £15 off ebay.
Both cases I used cameras that replaced a number plate light. Worked well enough, but it would be nicer if they were dead centre on the car.
Like some others have said – there will be an owners forum and a step by step guide somewhere.