"The investigation is in its early stages and the cause of the fire and the death remain unexplained at this stage."
After the car was found, a police spokeswoman said "enquiries were ongoing".
The victim's identity was not yet able to be released, he said.
If anyone has seen the car they are urged to contact Auckland Crime Squad on 09 302 6557 or to provide information anonymously to Crimestoppers on 0800 555 111.