Curious that he would abandon his vehicle in the wilderness and light it on fire, unless he wanted to draw attention to it (either as a diversion or as an ambush trap).
If he was trying to hide in a rural area, why draw attention to himself? If he wants to pursue his vendetta, I would think he would remain in the city. Of course, he could have already set off in another vehicle well before the fire was detected, and eventually traced to Dorner.
His actions seem purposeful, although it's not clear how much advance planning has gone into his rampage, or if he is just improvising now.
Crazy stuff...
ADG