Managing director of the provider Tina Shortle said that devices including mp3 players and mobile phones are "a thief's dream".
"They are easy to snatch, easy to conceal and because they are desirable items, easy to sell on," she explained.
"We strongly urge drivers to take 30 seconds to check their vehicle and to lock their gadgets in the glove box or boot when parking, even when leaving their car unattended at a petrol station."
Previous research by swiftcover.com claimed that drivers in the UK could be saving an estimated £1.9 billion on car insurance premiums by shopping around online for the best products and prices available to them.
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