why do you think it was Really developed ??
I think it was so that cars with dual turbos, and big headers, coulkd be worked on in pit stops.. that and for protection from tubing that came close to other components, in cars, ie brakelines, MC, throttle cables.. stuff like that..
Circle track cars have thin aluminum firewalls, and high interior temps, it would help with that..
I think it looks cruddy on bikes unless the pipes are running underseat.. Want a cool look... laverda sandblasted the pipes on the Jota, then chromed them.. they looked like wet chrome.. that looked cool..