..... if I'm not going to install a rearview camera? Justg wondering if it's necessary or not without the camera.

It's not necessary, but you may have problems with the arrow marking your position pointing the wrong way if you back up for a long distance. I think there are some accuracy issues with distance travelled and time to destination estimates, but nothing major. The reverse wire isn't usually too hard to find in most cars, though, so I always hook it up in my customer's vehicles regardless of whether they have a camera or not.

Reverse wire is not soley for backup cameras. The Pioneer needs to know which way your car is traveling when it senses the speed pulse. Otherwise it'll skew your accuracy.

Cool, thank guys. I'll just go ahead and hook it up.