Data revealed that the Metropolitan Police closed 89% of car theft cases last year without even identifying a suspect.
He also found that only 2.4% of vehicle thefts result in charges against someone.
According to the Liberal Democrats, it is the worst record of any police force in the country amid calls for the Metropolitan Police to set up a car theft task force.
A separate analysis of Home Office statistics by the Liberal Democrats found the Met closed 24,499 cases of vehicle theft in 2021, and in 21,757 of them no suspects were identified.
Only 598 cases resulted in the indictment or summons of a suspect.
Over the past five years, a total of 124,548 cases of vehicle theft have been cleared by the Metropolitan Police without a suspect being identified.
Liberal Democrat Assembly Member Caroline Pidgeon also found that more than 10,000 thefts of catalytic converters were recorded by London police in 2021.
The party calls on the police to “get this scandal under control” and urges them to set up a car theft task force.
Liberal Democrat MP for Richmond Park, Sarah Olney, said: “The Met needs to get this scandal sweeping our city under control.
“My inbox is full of drivers who have been victims of auto theft or catalytic converters without justice being served.
‘Londoners expect their streets to be safe and their valuable possessions safe from criminals, but based on these figures the Met is failing.
“People’s cars are often their most prized possessions, and it takes them months or even years to save them. Stealing them without justice is a shameful situation.
“I want the Met to set up an urgent auto theft task force to catch these criminals and bring justice to the victims once and for all.”
It comes as the Liberal Democrats discovered last week that the Metropolitan Police are the second worst force in the country at closed stations.
He revealed that 36 police stations had closed in the capital since 2015, including 31 in 2017.
The Liberal Democrats sent a Freedom of Information Act (FOI) request to every police force nationwide and discovered the startling findings about the closure of Met police stations across the city.
The Metropolitan Police have been contacted for comment.