Drivers have been told to break bad habits that make them targets for smash-and-grab thieves who have snatched everything from 50p to £10,000 from parked cars.
Theft from cars is one of the biggest problems in the Royal Borough and January saw 41 smashed into during one week.
An awareness campaign has now been launched to educate drivers that leaving any valuables on display can be an invitation for criminals.
Thames Valley Police PCSOs and Royal Borough community wardens spent yesterday afternoon patrolling Maidenhead car parks and streets.
Any vehicles with valuables left on display, or unlocked, will be sent warning letters highlighting they present easy-pickings for thieves.
Within seconds of arriving at The Magnet Leisure Centre's car park in Holmanleaze, the team found three cars which would attract an opportunist thief.
One motorist had left a sat nav system on the dashboard, some headphones on clear display and bags on the back seat.
Another left a handbag in their car and a third had left their passenger side window open.
The team logged the details of each car and will sending a warning letter to the registered owner.
"I guarantee we'll come across 15 of these similar to that," said PCSO Jason Miller, who was on the operation alongside PCSO Graham Knight.
"This is what we're up against."
He said police advice is to now remove all valuables from vehicles and remove any sign of them, including tell-tale sat nav sucker marks on windscreens.
The team said they have seen one car targeted for just 50p. Another, parked in Bray last year, had £10,000 taken from it after the cash was left by a man about to travel abroad.
PCSO Knight explained that there has been a reduction on the levels of car crime since but it is still 'an on-going problem'.
"This is an issue," he added.
"We'll never get rid of it but we can reduce it."
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