So she had some sort of explosives or accelerant in the vehicle with her. Either this was a suicide, in which she crashed and torched herself (which is sort of unlikely), or it was a murder.
If it was a murder, that means the terrorists are still nearby and at large. It also means they were scared enough of what she knew to need to kill her. Hopefully the FBI will be able to unravel this one as quickly as possible.
Don't bet on it, as a friend (L.A. County Sheriff) said to me, "the FBI couldn't follow a menstrating elephant in a snow bank"!