Where is the sensor for the trunk's FAST key located?

I'm thinking about swaping a spoilered trunk with a non spoilered one but I'm not sure what the deal is with the sensor. If its located within the trunk lid then I'm guessing that we'll have to have it reprogramed but if its somehwere else inside the trunk then it should be ok...

Has anyone experienced this before?

 

according to the owners manual its in the bumper area

 

If you stick your head into the trunk you can see it sitting up underneath the window there.

 

That is one of the interior transmitters. The one for the trunk is located in the bumper area. Page 3-17 of the 09 Owners manual shows the locations of all 5 transmitters (Internal: Center Console, under the rear deck lid External: one in each of the front door frames, and one in the rear bumper)