The road from Camaya to Bagac isn't paved, not even a decent dirt road. Certainly not something an ordinary vehicle can pass through. I've only gone as far as Camaya Coast so I can't vouch for the road condition for the entire stretch, but from what I saw, the forest trail is narrow.
So you can have an idea of how the road looks, here's a screenshot from Google Street View:
The paved road ends exactly at the entrance of Camaya Coast. From there, it's all jungle, which I think is what you're looking for anyway.