Just adding a bit of content. I threw in bumper sensors on my last 2010 Prius - and this is a fairly nice mod - it transposes a real distance (in meters) to your 'target'.

 

I won't be doing it this time around (camera is good enough - and it takes time to pull the stuff) - but for anyone mechanically inclined, it's a basic low cost mod that shows how far you are from hitting that thing behind you... around $50 on EBay - and they have different colors to match bumpers (mine was great - your mileage may vary).

 

There are lots of parking sensors on EBay - just search parking sensor. This particular one can be found Google searching 'autodvdgps'. I do not highly recommend them - as the response time lags incredibly - but if you are a patient person, the product is very cool....

 

http://priuschat.com/forums/gen-iii-201 ... mod-2.html

 

 

Picture on bumper