"It was a bit scary, but just incredibly annoying," Caughley told the Herald.
"I never usually drive that way to golf, I often use the Waterview Tunnel."
He said immediately his car stopped, and there were "a lot of funny noises and lights flashing".
"I've had it for about five years and it's my pride and joy, it's the first time I've done something as silly as this. It's a bit gut wrenching to end up looking at it sitting in this water."
A woman in another vehicle called emergency services when she spotted Caughley and another car which managed to get stuck travelling in the opposite direction.
Caughley was stuck in his 2012 Aston Martin for about 90 minutes while the fire brigade cleared the water.
Water seeped through the doors and he said he could feel it on his bottom.
"It would have been knee-deep, about 18 inches."
He said it was unlucky, but "these things happened".
"The fire brigade were amazing," Caughley said.
"They pumped out the road and road repairs came and unblocked the drains."
The car was taken to a tow yard and will be assessed for damage on Monday by his insurance company.
"There's no damage you can see externally, no panel damage, it looks just as it always did but internally it's the carpets and electronics."
Northern Fire communications spokesman Murray Bannister said the two cars got trapped at Trenwith St, which runs under the Southern Motorway, in Otahuhu, about 7am.
Bannister said there was no threat to life or limb.
A police spokeswoman said the water was cleared around the vehicles with a pump about 8.30am and tow trucks had been called.
She said with the wet weather in the upper North Island, police would ask motorists to take extra care in the conditions.
"If you do have to drive, please keep your speed down, and maintain a safe following distance.
"Take note of any road closures and cordons, and avoid travelling through any flooded areas. Sudden downpours can cause surface flooding in an instant, so ensure you exercise caution and pay attention to your surroundings."
More wild weather to come
Auckland's wet and wild weather isn't over yet.
A slow moving front lies over Auckland, Coromandel Peninsula, Waikato and Western Bay of Plenty today, bringing a heavy rain watch with it.
Metservice meteorologist Nicole Ranger said people in those areas could expect periods of heavy rain, possible thunderstorms and some heavy downpours.
Some of these thunderstorms could be severe, producing localised downpours of 20 to 35mm per hour.
"Wind shouldn't be too much of an issue, it's the rain that's more the issue."
Ranger said they hadn't received any reports of tornadoes, but a few thunderstorms had gone through the night, and rainfall had been particularly heavy around Auckland.
Ranger said Northland and Gisborne could expect some showers today, with heavier showers in the afternoon.
"Southern Taranaki to Wellington is actually looking okay, it will likely fine up today. The South Island is also looking fine."
There's more wild weather to come for Auckland, as another active front moves towards the city on Monday.
A Northern Fire communications spokesman said they'd received 20 to 30 weather-related callouts overnight.
Still without power
Today's wet weather follows a night of weather mayhem that blasted Auckland on Tuesday with winds gusting up to 213km/h at the Manukau Heads.
It tore roofs from houses and uprooted trees that came crashing down on powerlines. At its peak 180,000 homes were without power.
About 10,000 Aucklanders are still without power.
Vector spokesman Iain Butler said more poor weather last night saw some new trees come down across parts of the North Shore and South and West Auckland, creating new outages.
"We also had overloading affect a substation in Henderson/Swanson as large loads were being brought back onto the network, impacting customers in parts of West Auckland, but was fully restored by 9.30pm."
The affected areas from the new outages overnight were largely restored now.
Butler said numbers without power were still extremely fluid, due to the new outages and ongoing restorations.
"Overall, progress is still expected to continue as outlined yesterday, with the backbone of the network nearly fully restored, and individual pockets of homes, and those without hot water, being progressively restored into the middle of next week."