In the world of FIA World Rally Championship, the Group B era was the Golden Age. In all reality, it was a touch of insanity. Introduced in 1982, Group B had very few restrictions on technology and design. Furthermore, only 200 cars were required by manufacturers for homologation. Weight was as low as was attainable, new construction materials were permitted, and there were no restrictions on boost. With so few constraints, some manufacturers went a little crazy. Just in regard to power, the unrestricted boost allowance resulted in horsepower increasing from 250 in 1981 to over 500 by 1986 -- the final year of Group B.
Lancia had come off of great success with the Stratos before Group B was formed.The 037 Stradale was the foundation for their next rally car iteration. It was a purpose built homologation car that would allow them to compete with as much advantage as possible in the Group B class. As such, it featured all the attributes of a no-compromise race car, while still complying to passenger car regulations.
The 037 Stradale was built with no compromise, even for the street. It was fitted with large Brembro Brakes, double wishbone suspension, two shock absorbers in each rear corner (!!), two 35-liter fuel tanks, ZF five-speed gearbox, and a 2.0L Abarth-supercharged engine. Even the body panels were constructed and mounted in a way to allow maximum access for repairs. Pininfarina was charged with the design of the car, and took full advantage of the loose material restrictions. They formed the bodies out of Kevlar reinforced fiberglass.