"The problem halting us was unfortunate - it is a new brand and a new motor that has not been used in rallying before. Fortunately it was an issue with a certain type of plug and we can go to a new type of plug.
"The feeling was brilliant in the car when it was going well. All the other systems worked perfectly.
"Some of our splits when the car was going well were right up there with the rest of the field.
"I just want to put a whole rally together and see where we are at."
Marston's team only completed the build of his Barina at the 11th hour and he expected to have some teething issues.
"My car was finished at 1am the morning before the event.
"We need to iron all of the issues out and get familiar with them. Because the engine package is new and the chassis is new to us you can't jump in and expect it to be perfect out of the box.
"Once all those things are ironed out it is going to be a really good package with a lot of potential. I think in the first year you are definitely going to see the older generation of car being very fast and competitive because they have had so much development for such a long period of time."
The AP4 cars are much more modern looking and, according to Marston, a lot more fun to drive.
"They are a different beast in terms of how they handle compared to a Group N or even a Group A car.
"They move around a lot more and it is quite a cool sensation - it floats, moves and pitches and rolls and gives you a lot of feedback."
With the spark plug issue now resolved Marston and Murphy will spend the next two weeks preparing for the International Rally of Whangarei, which doubles as the second event on the New Zealand Rally Championship.
Marston is looking forward to seeing both cars lined up next to each other.
"That is really cool - it is great we have done Otago. To have both cars there and the full team assembled will make it feel official that we are a two-car team."
