The group's Volkswagen Beetle Cabriolet, which The Wiggles used for promotional appearances, will be on sale on eBay for 10 days starting Dec. 7, The (Sydney) Daily Telegraph reported.
Blue Wiggle Anthony Field said the charity was very special to the group.
"Sudden infant death syndrome is a cause that's extremely close to our hearts," he said. "My niece Bernadette Field died from SIDS at the age of 8 months in 1988 so SIDS and Kids is a charity we've supported since we started out 21 years ago."
News Limited motoring editor Neil Dowling said, "Car experts say a used VW Cabriolet would normally sell for about $4000, but one owned by the Wiggles could fetch up to $40,000."
The winner will be announced ahead of The Wiggles' Sydney show Dec. 23.