Angus Mason was found slumped over the wheel on Sandalwood Drive, at 11.30pm, on September 24, and police were unable to wake him.
When they opened the door they smelled cannabis, and found 16 grammes of the drug in the footwell, as well as 13 grammes of amphetamine.
A police drug expert ruled that the 21 per cent purity of the amphetamine meant that Mason was planning to sell the drug.
Chris Lacey, mitigating, said: “He says “I am a drug user. I have no income from the state benefits because I struggle with the forms.””
The court heard he has a previous conviction for possession with intent to supply.
Mason, 35, of Carsic Road, Sutton, admitted possession with intent to supply cannabis and amphetamine, when he appeared at Mansfield Magistrates Court, on Wendesday.
He was given unconditional bail to appear at Nottingham Crown Court, for sentencing, on August 1.