The more information released, the more lies are told. This looks like murder. Check the husband, the car, the lobbying firm. Antifreeze is extremely unlikely to catch fire. Something caused the woman to be unable to leave the vehicle before the fire and I suggest it might be drugs, strangulation, bullets, blunt force trauma, knife wounds or some other cause. The fire seems to be something that was set to cover up the cause of death. I’ve watched enough crime shows on TV (all the CSI’s and others) to know there must be forensic evidence to indicate a better cause of the fire than headlights igniting antifreeze. Keep investigating and tell us what really happened when you have a better clue.
In my area, any "unattended, unexpected" death is treated as suspicious until proven otherwise.
For example, if a 37 year old woman is found lying dead in the floor of her home with no obvious cause of death, it is treated as a suspicious death. Then if the autopsy finds that she died of a massive brain hemorrhage resulting from the rupture of a malformed blood vessel probably present since birth, the "case" is closed. On the other hand, if she is found to have died from a massive brain hemorrhage caused by blunt force trauma to the head, then evidence has been preserved and law enforcement has the beginnings of a case. There is no "Ooops, sorry, we messed up," no apologies to the family and the community.
It strikes me as an eminently sensible way of handling these unfortunate events. Better to have ten "suspicious deaths" that turn out to be natural causes than one case in which a murderer goes free due to law enforcement's wrong assumptions.
In this woman's case, sure it is entirely possible that she could have died from something like that unexpected unsuspected blood vessel issue. It surely stretches credulity that her vehicle would then catch fire with her in it, just at that precise moment. Then to say that her headlights ignited her antifreeze, well, please! What did she have in there, rubbing alcohol? The only antifreeze deaths I have ever heard of were from ingestion, not ignition.