Police said the car, which crashed through the first set of glass doors of Willy Brandt House, the SPD's headquarters, was laden with petrol canisters and gas cartridges. The building's sprinkler system extinguished the resulting blaze.
Authorities did not identify the man, in part because of a policy of limiting public communications in cases involving suicide, attempted or otherwise, saying only that he was 58 years old.
A police spokeswoman said investigators had found nothing to cast doubt on the man's claim that he had been attempting to commit suicide. The incident did not appear to be an attack, she added.
It was unclear why he had chosen the SPD, which is about to start negotiations on governing for another four years in coalition with Chancellor Angela Merkel's conservatives, as his target.
The man was taken to hospital for treatment for superficial injuries to his head. Nobody else was hurt. Police launched an arson inquiry and state security services were also investigating.
(Reporting by Ralf Bode, Georg Merziger and Hannibal Hanschke, writing by Thomas Escritt; Editing by Robin Pomeroy)
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