http://smile.amazon.com/gp/product/B00U ... ge_o03_s00
Fun and inexpensive mod is to install a backup sensor. I got the above and have had it installed (easy) for several days now. I like it. It is not factory quality but it is pretty darn nice and the best part is it works well*!
[*These sensors need to be mounted higher than factory ones. At least the ones on our Freestyle are at the bottom of the bumper]
After installing and (gulp) drilling holes in my bumper cover (and of course, 1 hole is a tad lower than the one next to it...yes, I measured and marked but obviously incorrectly) and committing myself to the project, whenever I put it in reverse it beeped. Couldn't figure out what the problem was. Figured it out today, the 2 center sensors are too close to the ground. If I turn the actual sensor itself, it still beeps because it (the bumper cover) is curved and the sensors pick it up.
(EDIT-after further testing, it seems I have 2 defective sensors after all. I will update with the result of any customer service I am provided with.)
The sensors themselves are held in the hole by friction rubber pieces. They blow. They need something better. As is, they stay in well enough, but work their way out with changing temps as evidenced today in the direct sun. Annoying is being polite in my description. To mount permanently will require some type of adhesive. I will adhesive mine when I decide on what to use. As of right now it seems I have messed with them enough (once inserted, I twist/turn them a hair to 'lock' them in even though there is no 'locking' going on at all.) that they are staying in pretty well.
Since I have removed the 2 defective sensors from the system (just unplugged them) the two outer most sensors are working VERY well. I really couldn't be more pleased with the system. The camera takes care of the center anyway, the outer two are to help detect what the camera doesn't see/show on those corners. As such, the system works brilliantly. I really recommend this inexpensive mod. Just use more care thatn I did, on your 2 center sensor placement locations and where you drill. The problem is the bumper itself is right there and it makes it challenging.
I mounted the module via 2 way tape to the rear 'firewall' (for lack of a better term) and ran all wires thru a rubber plug in the spare tire well. Same one I used to pull the power/video cable thru from the camera.
The speaker I mounted in the rear right cubby by the hatch. Popped a 3/8 hole, shaved the corners of the speaker plug so it fit, and fed the wire behind the panel and to the module. The 'speaker' (really a piezo buzzer) has a 3 position switch that has OFF, LOW and HIGH volume functions. The switch is not labeled.
And it doesn't look too shabby, either.
'04 Escape XLT | V-6 | FWD | Factory Bug Shield | Boss Audio BV9384NV double din touchscreen w/NAV | Esky EC170-08 High Definition Color CMOS Waterproof Car Backup Camera | Geartist GTS8500b Reverse Backup Radar Sound Alert | CIPA 36400 Auto Dimming Rearview Mirror with Compass and Temperature | carfieldenterprise.com Strut Tower Brace