I think the person who took the car back most likely had no idea about the abduction; I suspect it was an employee (or close friend) of the abductor. That's why it was driven in the middle of the day.
I have always felt that the person or persons who abducted Jennifer never thought that the Kesse's would respond to Jennifer's disappearance as quickly as they did......By 10:15 am Tuesday they were on their way from Bradenton to Jennifers, that would just be around 2-2 1/2 hrs if she left for work between 7:30a-8:00 am.....They probably thought that they had as much time as they needed to get the car back, check for anything that might have been dropped during the abduction , ie, if you believe that she was abducted on her way to work....I feel that her abduction was taking place when the cell phones were turned off about 40 min after talking to Rob....
Many people seem to believe the driver of Jennifer's car was just that a driver and was clueless about what had just happened to Jennifer.....It is beyond my imagination that someone would take the chance that they might be stopped driving a missing person's car at 12 noon, unless, they thought that they had more time before she was listed as missing....Then again, I cannot imagine that someone would drive a car without details and questions answered as to why.....Perhaps they were paid and money talks......The person driving her car could also have had dealings with abducting people in the recent past and was casual about it ....