I put in a double DIN Alpine ILX-650W into my 2000 Boxster S. (See Photo) I moved the factory radio to amp interface behind the radio where you can't see it but it allowed me to do the install without making any changes to the amplifier wiring. Its not perfect but allows for a much easier radio install.
Note: Make sure to keep away from the airbag unit just behind and below the center console.
I also added a review camera and hooked it to the Alpine unit.
The double DIN kit was on Amazon for $25 or so. It matches the Boxster S perfectly. I put the AC unit in the lower insert as you can see in the photo.
Double DIN kit Link:
https://www.amazon.com/gp/product/B01N3T0ZBW/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1
I removed the Radio cut the center plastic and the Double DIN radio fit perfectly.
I also recommend to get the wiring harness for the hookup as well as the bypass unit. Note that the Red and Yellow wires have to be switched for the unit to work properly and maintain the memory on the Alpine Radio. This may be due to Alpine but I think the harnesses wires switch the Key Insert Power and the direct battery power. I also added the microphone and BT Apple CarPlay connection as you can see. You can get the USB hookup on Amazon as well.
