Took at a look at the car today. Looks like the fire started on the passenger side near the front of the engine compartment as evidenced by how the paint is most damaged in this location. The lighter paint damage on the driver side was already there and is is a result of 28 years of heat from the turbo slowly baking the paint from the underside of the hood.
As you can see from the bottom photo, the distributor, coil, headlight motor (pop up lights up/down), and power steering reservoir are the major components residing on this side of the car.
The fuel injection/fuel lines are on the top of the engine pretty much square in the middle of the engine compartment. The electric fuel pump is under the car.
To be honest, I am not quite sure what to think regarding the cause of the fire. Of course, nearly impossible to discern much for certain since everything in that area is burned, charred, or melted.