Please put the crackpipe down. While it is generally a matter of opinion, I would have to suggest that 1986 was the year of the best WRC cars. Ford RS200, Lancia Delta S4, Audi Quattro, Peugot 205 T16!!! All much more impressive than any of the cars before or since, other than possibly the original Impreza/Lancer battles of the late 90's/early aughts. Also notable is that 1986 was the last year that there was a WRC event in the U.S. and was the last year of the Group B cars.

1986 World Rally Championship season - Wikipedia, the free encyclopedia

-Brian