With all three NZV8 races on rain-soaked Sunday, John Whelan, of Dunedin, commended his Tulloch Motorsport team for performing some "mad wheel changes" to convert his Ford from slicks to wet tyres.
In race one Nelson's John McIntyre paid the price for staying in the slippery slicks as what had been drizzle became solid rain, just as the field completed the rolling start.
McIntyre was past pole-sitter Angus Fogg and had a 100m lead by the time he came around the last corner before the start-finish straight, but the previously-damp line on newly-sealed tarmac offered absolutely no traction this time around.
"It was like driving on glass.
"I'd backed off but the car just aquaplaned and we were in the wall.
"Others were spinning in exactly the same place, and bouncing off our car," McIntyre said.
Two more DNFs for him in a leased car and two wins and a ninth for Queensland-based Craig Baird means McIntyre now trails in third, and Baird leads the championship by 113 points over Christchurch's Eddie Bell.
Whelan's first two races saw him 14th and 12th respectively before he hung on after an off-track dive to finish 10th in the reverse grid final.
"We went three wide round the loop and on exit there was no room for me to go," Whelan said.
Although he was 16th overall for the round he still remains 19th in the championship - the two DNFs at Invercargill last weekend keeping points down.
Grant Aitken, of Queenstown, had a "handicapped weekend", when a new gearbox and clutch provided a result opposite to the desired effect of making the Mitsubishi Evo 9 run faster.
"There was something wrong with the new combination.
The gearshift was like a truck's: ponderously slow," he said.
His team discovered at the production racing series' culmination that his boost had slipped off its normal boost rate and the mixture of mechanical woes saw him slip from first to third overall.
Aitken said he prefers the more technical tracks of the final two rounds - Manfeild (February 13 and 14) and Taupo (March 20 to 21) - and is confident he will be back up to speed for them.
Allan Dippie, of Dunedin, achieved his goal of getting in some track time driving his Porsche 996 before the Bathurst 12-Hour event on February 13 and 14, by competing in his second round of Porsche GT3 racing.
The two consecutive weekends couldn't have been more different weather-wise but they meant he raced in brilliant sunshine and then in wet conditions this weekend.
Dippie enjoyed the rain-sodden track, as the Porsche 996s have ABS, unlike the later model 997s, and it evened up the gap between them, he said.
In the last race his clutch blew which he put down to the wear and tear of the "flat changes".
The GT3s were "pretty tough on the clutch because you change gears without lifting off the accelerator."
The Dunedin motorbike contingent fared better at a predominantly dry Teretonga with Super Motard South Island Cup contender Hayden Scorringe having his "best weekend so far".
He wound up second overall and broke the lap record for his class, setting a time of 1min 9.1sec.
"It was probably the best racing I've ever been part of," he said.
Fellow class rider Scott Baird achieved two fourth places before a crash put him out of the third race.
In the 125GP class, defending champion Tim McArthur continued his battle with leader Alastair Hoogenboezem, of Christchurch, but retained his second place in the series.
A DNF in the third race means he now trails Hoogenboezem by 54 points.
