Martin Lewis has called on drivers to take matters into their own hands and take steps to slash their car insurance costs, which could save them hundreds of pounds. While average car insurance prices have fallen from their peak a few years ago, many drivers are still struggling with the high costs. Money Saving Expert Martin Lewis has now urged motorists to renew their car insurance policy at one specific time, as it could save them hundreds of pounds. One driver who had used the method managed to cut their car insurance costs from £913 to just £445, representing a huge 49 per cent saving. Another was quoted £555 for car insurance, which plummeted to £222 when they checked 25 days in advance.