Over 100 illegal car modifications were made in Hertfordshire over the last year, new research reveals.

A Freedom of Information request has revealed the number of modification offences that were reported – ranging from tinted windows, to changing the colour of car lights.

All modifications to cars must be declared to car insurance providers, as they can result in fines if not.

The data collected by comparethemarket.com shows that Hertfordshire Constabulary ranked 25th out of 36 police forces reporting the most illegal vehicle modification offences found in their area.

In 2020 there were 123 modification offences reported in Hertfordshire, making it 103 offences per million people.

Specifically, illegal licence plate modifications appeared to be the most common modification in Hertfordshire, with 69 offences reported.

Illegally placed tinted windows were also highly recorded, with 34 modifications found in Hertfordshire.

Modifications to exhausts and lights had 10 recorded cases each.

Dan Hutson, head of motor insurance at comparethemarket.com said: “Modifications tend to fall into two categories: performance or cosmetic, but any modification, no matter how minor, should be reported to your car insurance provider.

“Lawful modifications can increase car insurance premiums, so it’s best to check with your provider before making any changes and there are some providers who specialise in modified cars. Modifications which are against the law are likely to invalidate any type of car insurance policy, so do your research beforehand.”

Across the nation, there were 13,000 fines handed out in the last year for illegal licence plate modifications.

Modified exhausts made up just 776 offences across the nation.