The mark 5 Mini is introduced in 1984, with 12-inch wheels, front disc brakes and plastic wheel arch extensions standard across the range. The 25 LE is introduced. Thousands attend Mini's 25th birthday party at Donington. BL changes their name to the Austin Rover Group.

In 1985, the City loses its central instrument layout - the last Mini to do so. But the Mayfair gets a rev counter. The Ritz LE is introduced.

In 1986, Mini production passes the 5,000,000 mark. Issigonis celebrates his 80th birthday. The Chelsea and Picadilly LE's are introduced.

In 1987, the Advantage and Park Lane LE's are introduced. Austin Rover Group becomes plain Rover Group.

In 1988, the second saddest year in Mini history, Sir Alec Issigonis dies. Red Hot, Jet Black and Designer LE's are introduced. Rear seatbelts and servo-assisted brakes become standard across the range. City gets headrests, radio cassette becomes standard on Mayfair. Tory government sells Rover Group to British Aerospace.

In 1989, Rose, Sky and 30 LE's are introduced (production of Mini 30: 3,000). Semi-official ERA Mini Turbo introduced with Metro Turbo engine and 93bhp. Huge Mini 30th birthday party at Silverstone. Flame Red and Racing Green LEs introduced, featuring Cooper-style paint and a rev counter.

In 1990, second versions of Flame Red and Racing Green LEs are introduced with Minilite-style alloys and a revised diff for better acceleration. They are joined by the black-and-white Check Mate and Studio 2 LE's. The Cooper makes a return as a limited edition of 1,000 cars (61bhp 1275 carb) prepared by Rover Special Products (RSP). A mainstream production model is decided upon with minor differences.

In 1991, the Mk6 is introduced.