Good friend of Ronnie Peterson who raced against, travelled with and supported him. Long-time involved with the Swedish Touring Car series as overall race director, he is still involved in Swedish race administration, whilst he is also involved in both historic racing and the management of the Knutstorp racing circuit. He is also still heavily involved with Peterson's legacy, as he is one of the major organisers and fundraisers for the fund established in his memory. Gunnarsson was a decent driver in his own right, and was a race winner in Swedish Formula 3, finishing runner-up in the 1971 series to Torsten Palm.

Biography last updated 4 Jan 2019