The 1966 Monte Carlo Rally... looks like it was run by some corrupted nationalists from France who handed the win to the Citroen, for having the same headlights it disqualified all the British cars for, which were legal for the previous two years

10 British cars were all ruled out of the prizes for alleged infringements of complex regulations about the way their headlights dipped:
   they used non-dipping single filament quartz iodine bulbs in their headlamps, in place of the standard double filament dipping glass bulbs, which are fitted to the series production version of each model sold to the public.

The 5th place car, a Citroen had the same headlight. It was given the win. Why? Well, the excuse is that the Citroen had that headlight optional at the factory, thus is was stock... and the British cars, though this was their 3rd year with these headlights, were not in compliance with the rules, which had been changed just prior to the race, and after the cars were accepted after their paperwork was entered.

According to new rules introduced at the end of previous year, any car entering the rally must come off a standard production line, with at least 5,000 cars being built to a similar specification.

The British cars were equipped with standard headlamps - but the only way of dipping them was to switch to non-standard fog lamps.

The confusion arose because the rally organizers initially said the race would be run under the old rules - and only announced the switch after entries had been accepted.

http://news.bbc.co.uk/onthisday/hi/dates/stories/january/21/newsid_2506000/2506863.stm

Thanks Steve R!