In a police interview played to a jury on Monday, the 71-year-old woman said she had finished shopping at Morrisons when McCann allegedly approached her car.
"He got into the passenger seat. I shouted, 'Get out, get out' and that is when he punched me in the face," she told Greater Manchester Police.
"He said, 'I don't want to do that, I have got a grandma'.
"He said he wanted a lift. He said, 'I don't want to hurt you. I have got a knife. I have killed somebody'."
The woman, who said she had been to church that morning, claimed she initially drove on the M66 motorway, but said she was made to switch seats with McCann as he wanted to buy cigarettes.
After they stopped at a service station, the alleged victim said she was driven to the entrance of an industrial estate.
"He got a bottle of wine out from my car and was drinking that while driving," the woman said.
"We got into this car park and he said, 'We'll have sex now whilst we are waiting'."
Woman, 71, 'punched in the face before being raped in car'