The car insurance market is in "turmoil", with some providers hiking their prices while others are slashing them to build up their customer base, a study has revealed.
The average of the five cheapest premiums for comprehensive cover policies sold directly has soared by 8.5% year-on-year to reach £1,034 for annual cover, according to the AA British insurance premium index.
But the average cheapest quote found on price comparison sites for someone with the same risks has dropped by 3.3% over the year to reach £631. It follows six months of "little movement" and young drivers have borne the brunt of the recent rises, the study said.
Premiums for young men aged between 17 and 22 stood at £2,792 in the second quarter of this year, while premiums increased for women in this age group and were £1,995 on average. A similar pattern was found on aggregator sites.
Simon Douglas, director of AA Insurance, said the market is "in turmoil".
He said: "Competitive pressure is leading some companies to make big premium cuts on price comparison sites so that they can increase their portfolio of customers. While this is great news for consumers, they need to make sure they're getting good cover, not just a good price."
Mr Douglas said "significant inroads" are being made to tackle fraudulent claims such as "crash for cash", although insurers are still handling "excessive" numbers of whiplash claims, which push up premiums.
The study said that application fraud, whereby buyers withhold or change information in order to reduce premiums, is also being targeted by insurers.
"We expect the industry eventually to have routine access to DVLA data and the sooner this happens the better," Mr Douglas said. "It will allow fraudulent applications to be weeded out. Insurance companies are already exchanging information about people who appear to be manipulating data in order to cut the price quoted."
Scotland remains the cheapest region to buy car insurance with an average cheapest quote of £727 while Greater Manchester and Liverpool are the most expensive regions, with average quotes of £1,648.