I ended up going with the 20% around the back and so far so good. I have no difficulty seeing out the back when backup up at night, so I'm happy.

I have been looking into retrofitting a camera, but it's like $500 and that's without any sensors. In general I'd love to add the CIC Nav system + camera to my car, but even with scouring ebay and whatnot, it'd be a $1500+ proposal...not sure it's worth it.