I've thought a lot about that car smell and what might have transpired to make it turn out the way it did.
I think we all agree that the smell was mentioned on the third 911 call, but that was after the officers had already been dispatched, and it may not have been relayed to them by the dispatcher. She also may have thought that since CA had mentioned the smell in her call, she would likely impart that information to the officers when they arrived.
When the officers did arrive, it did not seem as if the smell of the car was mentioned by family members. The car was in the garage, but the door was closed. If anyone had noticed the smell, someone may have told them the car had had garbage in the trunk when it had been towed. I got the distinct impression that the car was downplayed, and not just because the central theme of the call was Caylee's whereabouts.
I'm not sure exactly when YM arrived on the scene, but he is an officer that deals with child neglect. Initially the entire family was indicating this was a possible kidnapping that happened at another location. KC and her car had ostensibly not been on the premises much, if at all, for a month. So I think the impression was that nothing about the Anthony home was viewed as a potential crime scene.
Obviously after riding around with KC most of the night, Yuri came up with a different theory as to what was going on. IIRC, he dropped KC back home around 2 am or so and he and the other officers picked her up after 8 am the next morning. At that point, there may have been time to reconcile the reports of the dispatcher/s who took the calls with Yuri's own report of the night before, but perhaps not. However, I thought at the time that the fact JA, who is a homicide cop, was there for the interview at Universal meant that LE suspected foul play.
They knew her car had been in impound for two weeks, but they were careful enough to have sent someone over to the tow lot to grab the garbage bag.
LE also knew when GA and CA had picked up the car, and that CA had admitted to some light "cleaning", so if they had any idea the Pontiac might have been a crime scene, they knew it had already been compromised. I think they were hoping to make headway questioning KC and getting her to admit what happened and did not realize she would become stubbornly uncooperative. They may also have given her parents the benefit of the doubt (seeing as how GA was ex-LE) and not thought that further cleaning of the car or removal of evidence would occur. They also had to reason to believe at this point that her parents would become increasingly uncooperative as the days went on; I think they genuinely believed that KC's parents were more anxious to find Caylee than save KC from being accountable for whatever happened.
I imagine that, in retrospect, they wish they had become suspicious sooner, but they might not have felt until they spent the time with KC that the car was that key a piece of evidence - literally everything she initially told them was that Caylee was with someone else - and it might have been contaminated in many different ways during the last 30 days.
