I would be going over that car with a fine-toothed comb. I would want to see all of its paperwork, numbers, titles, work records, (yes, even CarFax). That car is currently the single most important piece of physical evidence. While we wait for the ME and lab stuff on Jessica. That car can tell a tale. The tale the car tells will be key testimony at a trial. I agree with others that the car is now contaminated/contestable evidence. But it still has a story. Any bullet holes? Were the windows shot out? Was it stripped in situ before being set alit? I don't know, off-hand, if it was a stick or an automatic. I don't know if it was front wheel drive, rear, or 4WD. I don't know how long Jessica had her license, or how much experience driving. I certainly don't like that there are photos of the car sitting on the ground at some spot where the flatbed dropped it off (complete with crowbar laying atop trunk).
Also, sleuthing, minus good old fashioned evidence, plus rumors, equals "what if's". It is the sleuthers way of killing time. For example, what if the 911 caller was actually reporting seeing a car that was actually driving down the road while on fire! And hence, the possible confusion over a person on fire moving down the road? Could explain the 911 caller not stopping to help. Could explain the 911 caller being quite sure it was actually a car that was on fire, even at the distance between car and call.
It seems to me to be a large part of human nature to try to create connections whether we are given two pieces of information, or a hundred. Plus, I am looking for creative writing points with this post.