The donut was just a celebration at the end of a good run for his fan club. There is one training run and three runs, each 20-25min (if I'm correct). And the Ford-driver wanted to cheer up the crowd.
The `63 Valiant is an original Austria export car (built in Hamtramck). Now it's modified with a 360c.i. engine (300HP), rollbar, racing seats, four speed, racing suspension, and Porsche brakes.
From the homepage...
The Valiant:
Year: 1963
Engine size: 5900 ccm
Horsepower: "enough"
Driver: Michael Mugrauer www.mopargarage.at
the gold Barracuda:
Year: 1965
Engine size: 6600 ccm
Horsepower: 400HP
Driver: Christian Zudrell
the black Barracuda:
Year: 1969
Engine size: 6300 ccm
Horsepower: ~390HP
Driver: Johannes Bigler