I don't think the CCTV footage is very useful. Police announced a while ago that they were out of leads. If they could recognize the make and model of Car 3, they would have a very strong lead.
If we think about this as an incident that ended with Danni vanishing, what we have is something that started at 11:08, as soon as Car 3 entered the Shell station. At that location, the GPS in Danni's car was disabled. It seems that this took 10-15 minutes to achieve. Car 3 left that location with confidence that no one would be able to track Danni using any GPS technology. Another point to consider is that Car 3 did not know that her phone was missing, so they would have been sure that her phone, if she had it, was disabled as well. Danni and her car vanished from that location at 11:24. I think she was alive when she left the Shell station, and I think that she knew that she was in trouble.