The driver of the car, a man, looked Kowalski in the eye and made pushing motions onto the back seat of his car. All the while, Kowalski could hear King's captive screaming, crying and banging.
Kowalski called 911 immediately and told the Charlotte County 911 call center what she had seen, remaining on the phone for almost nine minutes.
But the information never made it to police patrolling the highway near where King's car was spotted because a 911 call taker did not follow procedure and immediately log the call into the dispatch center's computer system.
The police who were nearby never knew they were so close to the kidnapped woman until days after Lee was murdered.
Lee was shot and killed less than three miles away from where Kowalski had spotted her. The young mother had begged for her life, and left clues for police in King's car, even calling police herself from her kidnapper's phone.
In 2008, the sheriff at the time, John Davenport of Charlotte County, described the breakdown of procedure as a "missed opportunity" and a tragedy.
"One dispatcher thought the other had sent it out," Davenport said. "The other thought she, the other had sent it out. And they didn't send it out."
The dispatchers who failed to relay the call were suspended and ordered to undergo remedial training.
Nathan Lee is seeking more than the $200,000 jury award in his wrongful death suit, an amount that's capped by state law. Although he acknowledged that he needs to care for his family, he also said the court action is about making sure that the system never fails another person again the way it failed his wife.
Through the Denise Amber Lee Foundation, Nathan Lee is advocating for better training for 911 personnel across the nation.
The Charlotte County Sheriff's Office had no comment on Lee's lawsuit when contacted by ABC News.
A jury has sentenced King to death for the killing, but he is appealing the conviction.
ABC News.com's Jim Avila, Rena Furuya, Andrew Paparella and Lee Ferran contributed to this story.