I think regardless of who actually did it, someone staying local or traveling hundreds of miles, there is so much area that should be searched. Just looking locally, if you pull up a map and locate Froggys, (take into consideration that a cell phone can easily be tossed from the window of a moving car, crushed by others or lost in a body of water) consider going North toward Linden. Do you see all that wooded area and those lakes/ponds? And from Froggys to where Ramsey splits with Linden Rd is only a 10 minute drive that is not in heavy use especially at that time of night. There are few businesses that might have cameras in between.
Obviously to the west is 295. Hop on that and you pass over the Cape Fear River, and takes you not only to Wade NC but it's only a 12 minute drive to 95, if that! 95 is gonna run you north or south along the entire east coast. 20 minutes north of this interchange is 40 which is going to run you west to the ocean or north east through Raleigh and on to Greensboro where you can pick up two major highways to run west on.
If you go South you are gonna head to downtown Fville. Not really ideal for this situation, but you can also pick up 95 this way, or you can head west through various side streets toward Spring Lake and the bases.
If you go West from Froggys you can jump right on Andrews Rd. It too is pretty desolate at night. You will run into McArthur and you can go in all directions at that point again, up toward Linden on an even more desolate road head down Honeycutt toward the base or McArthur/McCormick bridge straight out to Spring Lake. You can also head back toward Ramsey St.
The location possibilities are endless. Look at those points and then see the massive areas that is possibly covered. I do not believe it would be hard to transport someone or a body that late at night from that location. Don't do something stupid and you won't get pulled over.
I believe something or someone is going to have to snap for this to be solved.