After retiring from Formula 1 Martin devoted more time to other business opportunities as well as his F1 commentary role on TV.
Brundle became involved in driver management, in particular he managed David Coulthard from 1998 until his retirement in 2008.
He co-owned a management company, 2MB Sports Management, alongside old teammate Mark Blundell. Their clients include McLaren test driver Gary Paffett and British Formula Three champion Mike Conway.
In January 2009, Martin announced his intention to step down in order to focus on his television responsibilities and his son's motor racing career.
From 1996 to 2004 Martin was a board member and then Chairman of the Board for the British Racing Drivers’ Club (BRDC), the owners of the Silverstone racing circuit. He was instrumental in the significant improvements to the venue and road system, and the retention of the British Grand Prix throughout that period.
Away from motor racing Martin was a shareholder with his brother, Robin, in the Brundle Group of retail motor dealerships until it was sold in 2006. The business had grown out of their fathers car dealership called 'John Brundle (Motors) Limited'. At its peak, Brundle Group operated franchises for Peugeot, Toyota, Lexus, TVR, Maserati, Honda and Škoda at a two-acre multi-franchise park at Tottenhill.