The Pontiac Fiero had a tendency of catching on fire, in the rear, because of engine failures. Specifically, the 1984 Models with the 2.5l 'Iron Duke' 4 cylinder engine. The connecting rods in the engine would fail, blow a hole in the engine block, leak oil onto the hot engine/exhaust components, and then catch on fire.
The Fiero had several issues but the biggest one was the poorly-protected passenger compartment. If the car got rear-ended, it would likely explode due to how hot the engine ran and there was no suitable firewall to protect the passengers. General Motors, being the jerks that they are, blamed every single fire, including ones that happened at GM proving grounds, on improper owner maintenance.
The Pontiac Fiero had a tendency of catching on fire, in the rear, because of engine failures. Specifically, the 1984 Models with the 2.5l 'Iron Duke' 4 cylinder engine. The connecting rods in the engine would fail, blow a hole in the engine block, leak oil onto the hot engine/exhaust components, and then catch on fire.