Oooh, for such a simple thing, this fix is seems like a lot of easy work. You'll need to remove the rear fascia. To avoid this happening in the future, the next time you go to the car wash and the Wand Guy shows up, ask to borrow the wand, and then smack him over the head with it. Twice. He either won't wash your car, or at the very least, won't break anything else.
Tools:
1 six-pack.
Torque screw driver with appropriate bits
Basic plastic trim tool kit
Socket set
An able-bodied assistant who won't drink your beer.
1) Raise the Rear Deck Lid.
2) Raise and support the rear of the vehicle.
3) Remove the Tail Lamps:
a) Remove the caps covering the tail/turn lamp mounting screws.
b) Remove the mounting screws.
c) Pull the tail lamp straight back to release it from the rear quarter panel.
d) Disconnect the electrical connector.
e) Place the tail lamp next to a cold six-pack.
f) Have a beer.
g) Repeat steps a-f for the opposite side.
h) When re-installing the mounting screws, torque to 18 in/lb.
4) Okay, back to the Rear Fascia:
a) Remove the (5) push-pin fasteners on the top of the fascia. A set of plastic trim tools (with one that looks like a little forked crow bar) is essential. Otherwise you'll need to buy extra push pins. These break easily on a good day.
b) Remove the (4) lower fascia fasteners on the lower/rear of the fascia.
c) Loosen the rear wheelhouse panels. You may need to remove the rear tires to access the screws and push pins.
d) Remove the nuts (3 on each side) attaching the fascia to the quarter panels.
e) Disconnect the electrical connector on the harness on the right side of the fascia that goes to the object sensors.
f) With the aid of the able-bodied assistant that isn't drinking your beer, pull the fascia rearward and place it on a towel, the grass, or just have them hold it while you down another beer.
Depending on how easy it is to access the loose sensor that Mr. Wand knocked out, you may be able to get it back into place between steps d and e. In that case, look for the retaining ring that is probably flopping around on the wiring harness. Place the sensor in it's receptacle and slide the retaining ring into place, securing the sensor. It might not be a bad idea to press against all of the sensor retaining rings while you're back there.
Have another beer and then reverse the disassembly procedure. When you get back to step 1, drink any remaining beers, then ask your assistant to stand behind the car as you slowly back out --to test the sensors. If you hit him, the sensor may be faulty or the electrical connector is still disconnected. Or, he wasn't paying attention because he was drinking your beer when you weren't looking. If that's the case, pull forward and place the car in reverse again.
On the off-chance he's still able to walk afterwards, help him get into the passenger seat and take him to the car wash. Call Mr. Wand over, drop the top, (for dramatic effect) and show him how you treat your friends. Repeat as necessary.
Good luck! (With everything. . . )
CC
exactly why I would never go to car wash. 8 dollar hr. kids washing "scratching" cars.
