Since S2 lived alone with his parents, and the living arrangement with a grown man and an abducted 11 year old boy in the home would obviously be untenable, it is no assumption to accept that the option of JEW remaining in that home more than 4 or 5 days was out. With the scrutiny only increasing after the abduction (missed likely by Axis II NPD S2 but not Axis II HPD S1), the only viable window for escape would indeed be immediately after the snatch. Not only that, a viable narrative does not include the accompaniment of S1 by S2 by virtue of the fact that he clearly did not. In addition, such a sequence is consistent with flight, especially by an Axis II Histrionic Personality.
Ergo, it is most likely that S1 departed in his own private vehicle, most likely down S2's own driveway, likely in a small blue sedan or Monte Carlo (this is a direct taunt and joke by S2), carrying JEW and this is important, in the front seat. I will explain in a bit. The vehicle likely reached the roadway within 4 minutes of the first contact with the victim.
His likely first leg was non-stop to near fuel exhaustion, where he would refuel and continue to the State of IL. Under any such public contact, he would not have allowed JEW to be seen.
~ svh