Shane van Gisbergen hates driving in the rain – not that you could tell on Saturday.

The Kiwi opened the weekend’s V8 Supercars round at a soggy Sydney Motorsport Park with wins in both 100km races.

Not since Sandown in November 2011 has the championship endured a full day of wet racing, but van Gisbergen mastered it in his Holden to claim his first set of back-to-back victories.

“I can’t explain why I go alright in (the wet),” said the Tekno Autosports driver, who started the pair of sprints from fourth and sixth respectively.

“I’ve never enjoyed it.

“It rained almost every race in Formula Ford in New Zealand and sitting in an open cockpit car was the worst thing.

“I do, though, enjoy floating the car around and sliding a lot.”

The result helped Holden secure the manufacturers’ championship for a fifth straight year.

Red Bull Racing’s Jamie Whincup, who finished fourth and third in the two sprints, extended his series lead to 69 points over Ford Performance Racing’s (FPR) Mark Winterbottom.

Yet the Holden star, who also broke Peter Brock’s record for most pole positions in Australian touring car history, maintains it’s still too early in the season to worry about the 2014 title.

“I’m not thinking about the championship at all – I certainly wasn’t being conservative out there,” said Whincup, chasing a record sixth crown this year.

“It was dog-eat-dog, I was trying to win that (second) race and the best I could do was third.”

Winterbottom was intent on regaining his spot on top of the leaderboard after losing it to Whincup last round, but could only manage two 12th-place finishes.

He’s 186 points ahead of veteran Craig Lowndes in third.

The day went a little better for his younger FPR teammate Chaz Mostert, who went from 16th in race one to second in race two.

Volvo endured a horror debut at the western Sydney circuit.

After qualifying on the front row for both races, Scott McLaughlin was forced into early retirement – the first with power steering failure and the second because of a popped rear tyre.

His teammate Robert Dahlgren’s day was also cut short after spinning out early in race two.

Holden’s Tim Slade was the slippery track’s first casualty after clashing with Ford pilot David Reynolds on the opening lap of the first race.

Sydney Motorsport Park – formerly known as Eastern Creek Raceway – has only hosted two championship rounds since 2008, the last in 2012.

It’s the first time, however, the category’s new generation of cars has raced at the western Sydney circuit.

The round closes with a 200km race at 3.45pm (AEST) on Sunday.