Wonderbra billboard

Proceed with caution! This new Wonderbra billboard has fender bender written all over it. Photo: Daily Express / ZUMApress

How do you top the 3-D glory of "Avatar"?

A giant photo of ample cleavage should do it.

Wonderbra unveiled a racy new 3-D billboard promoting its Full Effect Bra in London on Sept. 13, the Daily Mail reports.

The 20-foot-wide ad features Brazilian model Sabraine Banado in the black bra, which is designed to make breasts look twice as big, according to the paper.

Steady, boys.

Wonderbra reportedly toasted the launch near Waterloo Station by passing out 3-D glasses to lucky bystanders while bra-clad models looked on.

But not everyone is happy about the up-close-and-personal boobs. Britain's Institute of Advanced Motorists -- which recently called Reebok's nude billboard a "deadly distraction" -- says it could be risky.

"For those motorists who don't happen to have 3D glasses in their car -- and most don't -- then as the image is slightly blurred, it will cause you to want to focus on it even more," spokesman Vince Yearley told the paper.

"I think it will be a distraction for men and women on the road. And you just need to lose concentration briefly while on the road and an accident could happen."

"As an iconic lingerie brand the 3D billboard is the perfect way to launch the campaign for our new bra," Julie Nolan of Wonderbra countered.

"It brings to life the product's benefits in a bold and exciting way."

Um, you can say that again!

In related news, check out Emporio Armani Underwear's racy ad campaign starring Megan Fox.