(NEW YORK CNN) Carl's Jr. is making no apologies for its new Spicy Burger television commercial, which features Hilton hotel heiress and reality TV star Paris Hilton in a skin-tight swimsuit soaping up a Bentley and crawling all over it before taking a big bite out of the burger.

The ad, which has been running in major markets since last week, has drawn the ire of television watchdogs, including the Parents Television Council.

"This commercial is basically soft-core porn," said Melissa Caldwell, research director for the PTC. "The way she moves, the way she puts her finger in her mouth -- it's very suggestive and very titillating."