I would not be surprised if there is an airport connection in this. Perhaps the driver worked for a package delivery company located at the airport and therefore knew the area roads very well, and even may have returned to the airport after the shootings.
As for Total Rental, it's amazing to think that the police, having had a description of a truck with Total [something] painted on the side, didn't simply pick up a phone book and look for local businesses named "Total [something]." Surely a vehicle rental firm with such a name would have jumped right out at them. But maybe not.
Seems like there was word about a week ago a witness said the vehicle said "Total" something on it.