Conversation so far:
What did Denny Hulme do after leaving F1?
After leaving F1, Denny Hulme led the GPDA (Grand Prix Drivers' Association) for a brief period.
Why did Denny Hulme only lead the GPDA for a brief period?
The cut and thrust nature of the post was ill-suited to Denny Hulme's gentlemanly nature and he did not fill the post for very long.
What did Denny Hulme do after leaving the GPDA?
Denny Hulme retired to New Zealand, returning to touring cars to race occasionally in the Benson & Hedges 500 race at Pukekohe Park Raceway in the late 1970s
What year did Denny Hulme start to race regulargly again after leaving F1?
Denny Hulme began racing regularly again in 1982 with amateur racer Ray Smith
What kind of cars was Denny Hulme racing in after leaving F1?
After leaving F1, Denny Hulme raced in Chrysler Chargers, a Volkswagen Golf, a Holden Commodore V8, a Rover Vitesse, Mercedes-Benzes, and ran Scania trucks.
Did Denny Hulme have any notable wins in the time period after leaving F1?
In 1986, Denny Hulme raced in the European Touring Car Championship winning the RAC Tourist Trophy, Hulme's fourth win in the event, 18 years after his third win.
What cars was Denny Hulme using during 1986?
In 1986, Denny Hulme returned to racing in the European Touring Car Championship in a Tom Walkinshaw Racing prepared Rover Vitesse. Hulme raced briefly for Bob Jane's Mercedes-Benz team.

Question: When did he stop racing?
Self-contained rewrite: When did Denny Hulme stop racing?