Having worked in a burn center, I also get nervous when fuel and my
skin are in close proximity. Diamond has approached the issue in a
different way than Liberty. My DA40 has metal tanks in the wings,
located between the two carbon fiber spars. The remainder of the fuel
system is external to the cabin. The fuel selector valve is connected
to the handle via long shaft, and resides, along with the boost pump,
in its own compartment.

To my knowlege, no Diamond aircraft has ever suffered a post-crash
fire.