I was thinking of a container mainly because he wouldn't want the remains to soil the car, or have any decomp in the trunk. And if it were being set up as a stranger perp who had been watching "the routine" and waiting for an opportunity to abduct Hasanni, then the stranger would have some connection to Hasanni and bury him in some fashion. It's too bad LE can't determine if any sheets or blankets are missing from the house, assuming that JC didn't give them any information like that. MOO
If LR had put Hasanni's remains in the car in any container of any kind --so that his body would have been not touching the interior of the car-- would cadaver dogs have picked up the scent? Now I'm wondering if they used cadaver dogs.
It seems that even if he put Hasanni in a bag or whatever, it would be hard to do it so antiseptically that some trace wouldn't have been on the exterior of the bag or container, and thus rubbed off onto the car interior. But then again....he was studying to be a medical assistant....