A Boxster may or may not
need a back up camera but I found that installing one was a fun project. The main reason I installed mine was that my car's double din Android head unit is capable of displaying a back up image. Now that it's installed I use it when backing up more than I thought I would even though I installed the camera more because I could and less because I thought I needed it.
You can take a look at the installation here;
https://rx19jones.wixsite.com/projectboxster/projectboxster4
cheers - dj