Introduced in 1982 by FIA, Group N is a 'standard' production vehicles for competition, often referred to as the "Showroom Class", with limitations in allowed modifications from the standard specs.
Honda Civic Group N Pair of Civics, Group N production class, taken at Thruxton 1993
Vauxhall Astra GSi Group N production cars, photo taken in the paddock at Thruxton 1993