To celebrate the 50th anniversary of the 1908 race, at the 23rd Tourist Trophy race at Goodwood on 13 September 1958 the 83-year-old Watson drove a lap of honour in his winning car, the Hutton-Napier Little Dorrit.

To celebrate the centenary of the race in 2008, the Veteran Car Club of Great Britain organised an exhibition at their Ashwell, Hertfordshire, headquarters on the history of the Isle of Man Tourist Trophy, 1905 to 1922.
 The exhibition was formally opened by one of Watson's granddaughters.
 The club rally was timed so that the veteran cars reached Ashwell at 3 pm on 24 September; exactly 100 years after Watson crossed the finishing line.
To celebrate the 50th anniversary of the 1908 race, at the 23rd Tourist Trophy race at Goodwood on 13 September 1958 the 83-year-old Watson drove a lap of honour in his winning car, the Hutton-Napier Little Dorrit.
To celebrate the centenary of the race in 2008, the Veteran Car Club of Great Britain organised an exhibition at their Ashwell, Hertfordshire, headquarters on the history of the Isle of Man Tourist Trophy, 1905 to 1922.  The exhibition was formally opened by one of Watson's granddaughters.  The club rally was timed so that the veteran cars reached Ashwell at 3 pm on 24 September; exactly 100 years after Watson crossed the finishing line.
William Watson (motoring pioneer)