Welcome. There was never a manual sliding rear window that I've seen. Like a horizontal sliding window every other pick-up has. Ford offered power verticle sliding or fixed glass only on the '07's. Not aware of an aftermarket manual slider as all Sport Tracs prior to '07 and all 2008+ all had power sliders. 2007 was the hit/miss year.
From here & other forums, I've learned some trucks were pre-wired for the power sliding rear window while others were not. To see if your truck was pre-wired, open the relay box under the hood (near battery) and see if you have wiring to feed would-be relay
#10 . Its the last relay position in its row, I believe the 2nd row of 4. You'll have to look down into the box, so maybe stand on a bucket. If you see the brass contacts where relay
#10 would go, your truck is pre-wired and installation of a power rear window is relatively simple.
If no contacts in the relay box, its not pre-wired, meaning at minimal you will have to add wiring to the overhead console or elsewhere for a switch, wiring at the fuse box, and more wiring to the rear of the cab to operate the motor. You'll need a different rear interior trim wall to accommodate the motor and tracks. The rear window appears (from inside the cab) to be 'bolted in', but in reality its sealed - the nuts on the studs you see secure the glass to the body while the sealant cures. So removal (and re-installation of the replacement window) is best left to the pros.
Sorry to be a Debbie Downer. My 07 also has a fixed rear window and every sunny 73° spring day I see other Sport Tracs driving with their rear window down... I kind of expected my truck to be pre-wired as it has all optional equipment outside of Navigation.
