If I install an aftermarket head unit (single din in the tissue box) will I lose the reverse sensor beeps? I do love those beeps..

if you get the signal from the stock speakers as "input" into your headunit then output from the headunit to "whatever" audio, then yeah, you can keep all audio output... to get this sort of thing to work isn't great at high volume, though.

Sounds like a good work around! So if I use a line converter I can then have an rca to 3.5mm audio jack cable into the front of the new head unit.

you could, but like I said, that sucks for audio quality especially at high volume if you're going to amplifying it etc

Could you wire the signal from factory unit to a small extra speaker you mount somewhere just for the beeps and then run the existing speakers off the new head unit?

that's definitely a better option...

Beep beep I'm a sheep

Or pick up off the canbus the signal for distance and replicate the sound yourself. I thought about it but cbf, I custom wired the reversing camera and have eyeballs so figured that was good enough

Thinking about wiring both outputs (standard unit and new unit) to the front speakers using this method

 

https://www.epanorama.net/circuits/linesum.html