I am still going with looking at the hubby. The fact that there seems to be a serial killer there might give hubby the idea that he could arrange a scene to "explain" a murder.
My reasoning:
The scene of the vehicle seems "staged". Her purse is in the car, yet her ID is strewn around, bank cards and credit cards are recovered. Her keys are there. Her shoes are an oddity that is out of place- maybe left there to help indicate a struggle. Open door also to indicate a struggle. Yet no other signs of a struggle.
There are 2 witnesses that report seeing the vehicle there, before the time she was supposed to have left for work. (It took 3 calls to LE, to get them to take a look at the scene). Only her hubby to say that she left for work at the usual time.
She was a mother with a young child and pregnant, so it is not likely that decided to run off and leave her child.
Other murders have shown that during pregnancy can be a risky time in a relationship.