American Idol's rock 'n' roll nurse Amanda Overmyer has hit a pothole on the road to stardom: The ENQUIRER has learned that she has spent time behind bars for DUI and has a long list of driving offenses, including one for going more than 100 mph.

Amanda's shocking driving record — six speeding violations, including one for going 100 mph in a 45 mph zone and another violation for running a red light — culminated in her arrest for drunk driving while speeding at 3:18 a.m. on Oct. 14, 2006.

She was pulled over for speeding by Crawfordsville, Ind., police officer Jared Colley, who noted that her eyes were bloodshot and her balance was poor.

Amanda posted a blood alcohol measure of 0.108 — above the legal limit of 0.08 — and spent six hours in the Montgomery County Jail before fiancé Casey Taylor posted her bail. She pleaded guilty.

And to make matters worse, nude photos of the wild child singer are being shopped around, The ENQUIRER has learned exclusively.

"If those pictures pop up on the Internet, Idol will have another huge scandal on its hands," a source close to the 23-year-old self-styled biker chick told The ENQUIRER.

When asked by The ENQUIRER about Amanda's nude photo scandal and DUI arrest, an American Idol publicist responded: "FOX has declined to comment."

Pick up the new issue of The ENQUIRER for more on Amanda's nude photos. Plus: Details about the Nov. 19 car accident that left Amanda in the hospital!