The Austin Montego 4-door saloon was introduced on 25th April 1984. At launch the top of the range, Montego Vanden Plas was powered by an updated version of the 'O' series 1994cc overhead cam engine. With a single carburettor, power was quoted at 102bhp at 5500rpm.

A 5-speed all synchromesh manual gearbox and power assisted steering was standard as was bronze tinted glass, a slide/tilt metal sunroof, electrically operated front door windows, central locking, 3-band electronic stereo radio/cassette player, 60/40 split rear seat with integral headrests and folding centre armrest and a side coachline with 'VP' motifs on each rear wing. The car was u pholstered in 'Raschelle' with wood fillets on all four doors and map pockets on the back of each front seat.

In March 1985 the Montego Vanden Plas 2.0 EFi, Lucas Electronic fuel injection model was introduced. This engine produced 115bhp at 5500rpm and mated to a 5-speed manual gearbox top speed was quoted at 112mph. The EFi came as standard with alloy wheels and leather upholstery whilst the trim in the carburettor model was changed from Raschelle to Box and Plain velvet. The EFi received as standard rear door electric windows and electrically operated and heated door mirrors.

On 26th February 1985 the Austin Montego Vanden Plas EFi estate was introduced. Mechanically identical to its saloon sister, the estate (Countryman) was fitted with rear self-levelling suspension, a roof rack and an additional fold-away occasional rear facing child seat increasing maximum accommodation to 5 adults and 2 children.

On 26th March 1986 a ZF 4-speed 4HP14 automatic gearbox was offered for the first time at extra cost. By this time production of the carburettor Montego Vanden Plas had ceased.

On 14th October 1987 the model name was changed to Austin Montego Vanden Plas 2.0i. An updated music system with Dolby and music search, newly designed alloy wheels and power headlamp wash were fitted as standard. The sunroof changed from metal to glass and electric operation could be specified at extra cost as could a new two-tone paint option,

Whilst Montego production continued until 1994, with the demise of the 'Austin' name and model changes, the Montego Vanden Plas models ceased production in October 1988 after 12,598 Vanden Plas saloons and 3,700 estates had been made.