"Certainly the car felt better when we started it up and we took it for a test run [on Tuesday]. It's running smoother and sounds better."
Whangarei is a familiar and favourite rally for Cox. It was his first with pace notes when he was 15.
"I've only missed it once since then, which was last year when we had another event on at the same time, so I know what the roads are like up there - they are my favourite roads in New Zealand. I've always had good speed up there and enjoyed it."
With eight drivers competing in the APRC round, including Perth based Kiwi Mike Young, Cox said the locals have extra incentive to do well.
"There are a couple of cars that are faster than the ones in New Zealand, but there's no reason why we can't beat them, so it's good to compare ourselves to different drivers, overseas drivers. There are some young drivers [in the APRC] and some older ones with experience so it will be good to compare how we are against them."
With Otago yielding just 17 championship points, a good performance in Whangarei is crucial.
"It's the last two day event of the year for us and we want to come away with strong points. For the championship to go smoothly for the rest of the year, it's very important that I go for a good result so we are looking for a podium in the New Zealand Championship - it's why we've done so much to the car, because it's such an important one."
Malcolm Read sat in the co-driver's seat in Otago, but he is alongside Young in Whangarei, so Cox is pairing with last year's co-driver Sarah Coatsworth.
The pair were together the last time Cox competed in the Whangarei event in 2014 when they showed good speed on the roads.
The rally begins tonight with the official rally start at 4.45pm at Pohe Island in Whangarei, followed by two passes of the 1.25km super special stage. The rally finishes at the Quayside Basin at 3pm on Sunday.
