So, I'm looking into installing a new head-unit in my 2007 S60 with rear park assist. I'm wondering, has anyone done this and retained the park assist feature?

As far as I can tell before I start digging into the dash and tracing wires, the park assist relies on the factory head unit as the brains of the system. It even displays "park assist active" as soon as I put it in reverse.

Has anyone reverse engineered the volvo OEM park assist to work with after-market stereos?

I figure, worst case is I have to install the factory unit elsewhere in the car to keep working as the park assist and then wire it to a speaker hidden under the dash near the driver, but that sounds like a horrible work-around.