GC Reverse Sensor

Wow, it's been a few years since I dwelt in the hallowed halls of
r.a.m.j+w. Be kind if I'm retreading some familiar territory. I spent a
couple of hours in google's newsgroup search trying to find any prior
threads dealing with this topic and could find nothing. So I ask for
your input.

I have a 99 Grand Cherokee. I asked on this list 3 or 4 years ago about
what was then called a RF Distance Detector. Brookstone had previously
listed one, but then pulled it for some reason. It didn't seem like
anything else was available at that time.

Well, I've been living in a cave Jeep-wise for the past couple of
years. I just discovered that there is a factory unit that was made for
the 2003 or 2004 Grand Cherokee (now called a Reverse Sensor, I
believe). I'm told this can be installed on any 1999 or newer GC.

I'm lookng for some information on how well this unit works and how it
operates *inside* the vehicle (I assume it has an audible warning; does
it get louder or faster as you backup closer to an object?). In effect,
is it worth the $299 MSRP?

Any comments, or pointers to a source of information would be
appreciated.

Thanks,

Bob