He said they have about 30 regulars among commuters heading over the hill "but there's been a lot of new faces today".
"Hopefully they will like the coffee and come back."
The couple offer Havana coffee and food, including "tasty cheese gems", giant seafood fritters and filled rolls.
Mr Peters used to work in construction as a concrete cutter in Wellington, so moving to coffee "wasn't that far along the alphabet".
Mrs Peters is a mosaic and glass artist, with her wares on display for customers to contemplate while she prepares their coffee.
"I've turned it into a kind of gallery," she said.
The pair say they love the coffee cart operation.
"We love working for ourselves," said Mrs Peters.
Mr Peters added: "We get to spend a lot of time together."
The Rimutaka Hill Road opened shortly before 1pm, with the Peters' staying open until that point.