Window tinting is one modification that can actually add practicality to your car as well as a cool new look - as long as you steer clear of the legal pitfalls.

THE LAW

The first thing to know is that window tinting can be carried out on any vehicle with glass, but there is the law to bear in mind. While tinting rear windows is fine, cars built after April 1, 1985 must have a windscreen that allows at least 75 per cent of natural light into the cabin and 70pc through the front door windows. This is to ensure good vision for the driver during the day and at night. After all, you wouldn’t wear sunglasses while driving at night unless you’re an idiot.

It’s illegal to fit or sell tinted glass that breaks these limits, which can be measured by the police using a special device. If your car does break the law, you can be asked to remove the tinted film there and then or face a prohibition notice that will stop you using your car until the windows are de-tinted. You could also face a fine and points on your licence.

DON’T DIY

Buying a tinting kit to fit yourself at home is not the best way to go about tinting car windows. There is a lot of skill in applying the film successfully so it fits accurately and without bubbles and ripples.

Professional tinting companies will have the patterns of almost all car windows, so they can cut the tint film exactly to the shape of the glass. They then use a liquid to prevent the tinting sheet from sticking to the glass until it’s in the perfect position. After that, the liquid is gently squeezed from under the film so that it adheres to the glass. Some companies also use a bonding method that gives the tint an even more permanent adhesion to the glass. You definitely don’t want this on your glass if it breaks the law, because you won’t get it off again by the roadside.

Once applied, the tint is very robust and will not scratch as the door windows are wound up and down, but the tint will scratch or chip if sharp objects are dragged across it. Only cheap and poorly applied tints will peel at the edges.

PRICES AND BENEFITS

Fitting a tint will typically cost around £300 to £500, depending on the size of the car, though some firms may charge more for the bonded type of finish. You probably won’t see that cost back when you sell the car, but there are other benefits to having car windows tinted.

One of the main reasons for tinting windows is greater security and privacy. If passers-by cannot see into the vehicle, they don’t know who or what is in there. This is good news for chauffeur-driven passengers and for van drivers who want to keep their cargo safe from prying eyes.

Another advantage is a quality window tint can reduce heat inside the car by up to 60pc, which is useful when you have kids or animals on-board. As well as heat, a tint can cut the amount of ultraviolet rays from the sun, which cause sunburn. The tint can also help lessen the fading effects of strong sunshine on dashboards, leather and other interior finishes. One last positive is a tint can lower the amount of glare for the driver, making it less tiring to drive on sunny days.

It all means window tinting, when done properly, can be one of the best modifications you can make – but remember to stay within the law.