The group suspected in the attack approached the car while the young men were attempting to help the girls park.
The mob attacked the two victims, and one or more of the assailants stabbed one of the men multiple times in the chest, police said. Investigators have had no luck determining a specific motive for the attack.
"There were so many people beating him he didn't even know he was stabbed until he got off of the ground and saw blood all over him and had trouble breathing," Reilly said.
The attackers fled in a white Chevy Tahoe, police said.
The stabbed man sat down on the curb while his friend ran north up Beach Boulevard for help, unaware at the time that his friend had been stabbed.
Two witnesses helped the stabbing victim until paramedics arrived and rushed him to the UC Irvine Medical Center in Orange. According to police, he was released about four days later.
Paramedics treated the other man for cuts and bruises.
The victims told investigators that the girls seemed to know the attackers, Reilly said.
"They probably all go to the same high school," Reilly said.
Investigators want to track down the girls to develop new leads in the case. The victims described the girls' car as a slate-blue, newer model sedan, possibly a BMW.
Huntington Beach Police described the suspects as white and Latino, ranging in age from 17 to 19 years old.
Police encourage witnesses or anyone with information to call Reilly at (714) 536-5940.