Mr Hosking replied it was the type of public transport that came along any time he liked, and Mr Cunliffe joked back: "You can come for a ride with me, baby, any time you like."
As Leader of the Opposition, Mr Cunliffe is entitled to the Crown limo service along with the Prime Minister and all other ministers.
Labour's public transport policy will shift funding from the National's proposed motorway work into public transport in Auckland, including a 50-50 share of the City Rail Link, rapid busways, electrification, and rail to the airport.
In answers to other questions, Mr Cunliffe revealed the worst job he'd had to do during the campaign was to clean up dog poo on his porch when he got home.
The piece of his clothing his wife would most like to throw out were three-year-old shirts that "haven't quite kept up with the campaign bulge".
He said the Olympic sport he would most like to win was swimming, and The Lord of the Rings would be his speciality MasterMind topic. He said House of Cards and Spooks were on his MySky series link recordings, and he had also liked Nothing Trivial.