Though she was cited for DUI Saturday morning, Lindsay Lohan hardly kept a low profile over the rest of the weekend.

On Sunday the actress, 20, hit a Memorial Day pool party for 944 magazine at Hollywood’s Roosevelt Hotel, where DJ pal Samantha Ronson was spinning. "She was in a great mood," says a partygoer. Insiders insisted she didn’t care about the consequences of her arrest when cocaine was discovered in her wrecked Mercedes convertible. Police found a substance they identified as "a usable amount of cocaine" in connection with the accident. Lohan was hospitalized for minor upper-chest injuries; her two passengers were not hurt.

Early the next morning, pictures were snapped of Lohan apparently asleep or passed out in the passenger seat of Ronson’s car, several "30 Days" sobriety pendants hanging from the rearview mirror.

According to the New York Post, Lohan had dropped her sunglasses and cigarettes on her way out of the hotel, then collapsed when she bent to pick them up. A bouncer had to lift her into the car.

The incident came just two days after the actress was arrested and cited for driving under the influence in Los Angeles after her Mercedes struck a curb and shrub on Sunset Boulevard around 5:30 a.m. Saturday.

In Touch is reporting that Lindsay Lohan is on her way back into rehab, after a wild weekend and her arrest for DUI early Saturday morning. Lindsay is due to check into Promises in Malibu this afternoon. This is the rehab facility that Britney Spears went to earlier this year.

This will be Lindsay’s trip to rehab this year. She completed a 30-day course in the Wonderland rehab facility in Los Angeles on February 16.

The actress was charged with a misdemeanor, a police spokesperson said at a press conference, adding, "There is a potential for additional charges." Blood was drawn from Lindsay in the hospital, and police are awaiting results of tests to see what substances were present. Her tentative arraignment date is August 24.

Some friends are hoping that Lohan, who checked into rehab in January, will again seek help. "The police intervening … could be the best thing for her," one source said. "I think she’ll have to do a real rehab this time, and not just a Hollywood rehab."

Lindsay’s parents were in court recently fighting for custody of Lindsay’s two younger siblings. Lindsay’s father has been outspoken sending messages to his daughter to get help, and offering his love and support. Watch his latest video message here.

Linsay was scheduled to begin shooting a movie called Poor Things, a crime mystery, with Shirley MacLaine and Olympia Dukakis, but with Lindsay in rehab she won’t be on the set. Now many are asking if Lindsay whether she is too much of a liability to hire for movie studios. Some also say Lindsay is box office poison with a string of movie bombs, the latest being Georgia Rule in theaters now, and bombing.

Shanna Moakler couldn’t help but take a shot too saying, "When you are making $8 million dollars a film … HIRE A DRIVER!!" Shanna goes on to say the "penis posse," which includes Lindsay, Paris Hilton, and others "…is going down one by one…and going to rehab or jail."

So, will Lindsay still be partying at PURE Nightclub in Las Vegas on July 2?

Lindsay Lohan was cited for investigation of driving under the influence Saturday and was slightly injured when her Mercedes struck a curb, police told the Associated Press. Is that Vodka company still going to sponsor Lindsay’s birthday party?

Lohan, 20, and two other passengers were in her 2005 Mercedes SL-65 convertible when it crashed at about 5:30 AM into a curb on Sunset Blvd., Sgt. Mike Foxen told the AP. The crash was Lohan’s third accident in about two years.

"She was cited and released because she has been admitted to a local hospital for minor injuries," Foxen said.

No one else was hurt and no other cars were involved, Foxen said. He did not have other details. Officers went to the scene after receiving a 911 call about the accident, Foxen said. He went on to say that Lohan will have to appear in court to answer the citation.

…but there’s now more…

In a press conference this afternoon about the arrest of Lindsay Lohan, cops say they found a "usable amount" of a drug they say was cocaine at the scene. Lt. Mitch McCann of the Beverly Hills Police Department would not say where the drug was found but it was "not on her person."

Police say that 20-year-old Lohan and two other adults were in her 2005 Mercedes SL-65 convertible when she lost control and crashed into a curb and trees in Beverly Hills, Calif. around 5:30 AM. After the crash, police say LiLo got into another car and was driven to Century City Hospital where she was treated for minor injuries that involved "something to her upper chest area." The two other people in her car were not hurt they said.

Officers received a 911 call about the accident and "tracked Ms. Lohan to the local hospital, where she was ultimately placed under arrest" for investigation of misdemeanor driving under the influence of alcohol or drugs.

Lt. McCann said it appeared as if Lohan was speeding and lost control.

Lohan was cited and released and will have to face a judge.

A rep for Lohan could not be reached for comment.

Welcome to the DUI club Lohan. She must have skipped AA to go drinking and drugging. If Lohan can heal up fast enough maybe she can join Paris Hilton in jail.