The law on car tuning and modifying is being firmed up – and a recent DVSA court case and subsequent conviction may have sweeping effects for our scene. Here’s the lowdown…

Let’s face facts; there isn’t a car out there that doesn’t sound infinitely more impressive, or perform significantly better than once it’s had the benefit of a decent exhaust system and remap. This trusty pairing are the very foundations on which the car tuning scene is built. Sure, stance and wheels get you kudos, but extra horsepower and the right soundtrack? That’s when your car really becomes yours.

In the mad old, bad old days, anything went. Want to remove your fully catalysed exhaust system and replace it with a swiftly bent length of scaffold tube? Be my guest, son! Fancy a remap that sounds like a machine gun attack in ‘Nam? Not a problem. And there would always be a friendly MoT station that would help get you through the test when the time came.

Now though, things are a little different, and a recent landmark case by the DVSA, or Driver and Vehicle Standards Agency, to you and me, saw a respected tuner taken to court and significantly fined for the crime of fitting a decatted exhaust and ‘pop and bang’ map. Two mods that can be seen at pretty much any car meet you care to mention.

Driver and Vehicle Standards Agency and Car Tuning

So why is this important? Well, it means the DVSA is looking at what the tuning industry is doing, and then looking to enforce it to the very letter of the law. To do this it has created a Market Surveillance Unit, and these crack investigators are scouring every website, every social media feed and even every magazine, to find tuners that perhaps are supplying things that are a little bit questionable. In the case of this successful prosecution, they achieved this by actually ‘mystery shopping’ the tuner in question with the Fiesta ST that they had bought specifically for the purpose! Safe to say that they’re not playing at it.

Rear 3/4 shot of flame shooting Liberty Walk Nissan GT-R

How does the law effect car tuning?

So does this mean we should all hang up our modifying spurs and quit messing about with cars for good? Absolutely not, I’m delighted to report, but it does mean that all of us can and should take a few sensible steps to protect the future of our scene. For drivers, that means buying mods and kit that won’t fall foul of the law. And for tuners and suppliers, making sure that customers know what they can and can’t fit to stay legal.

De-cats are a really simple one; if you want to take the catalyst off any car and replace it with something else, that ‘something else’ really needs to be another kind of catalyst. If the car is registered after March 1st 2001, it also needs to be EC marked and type-approved. If it’s registered before that date, it doesn’t need to have the EC mark, but it does need to pass the relevant emissions test come MoT time. Put simply, either way, the only option here is to run a sports cat. It’s going to hurt a little compared to the far more reasonable price of a de-cat alternative, but the smug feeling you’ll get come the annual test, and the warm and fuzzy glow that you’ll get from saving all those polar bears and ice caps the rest of the time will make it all worthwhile.

And what about remaps?

As for your choice of remap, it’s worth thinking a bit laterally here, too. Having a vehicle equipped with a ‘pop and bang’ switchable option isn’t illegal in and of itself, as long as you don’t choose to use that option on the road, or in an area that might cause a public order offence. If you can go for software that allows you the extra torque and power for road use, perhaps combined with a gentle over-run burble, you’re going to be golden – then save the noises for the showground. That said, it’s probably not going to do an awful lot of good for your lovely new sports cat…

Police Ford Ranger Raptor chase

What are the repercussions if caught with an illegal modification?

Those are the two biggest DVSA bugbears at the moment, and it’s worth getting on the right side of them. The fine for the driver of an uncatalysed car is £1000 – and if the copper that stops you is having a bad day, then they’re also within their rights to impound and tow your car there and then. It is, technically, un-roadworthy, after all…

How to buy legal car modifications

How do you choose the right parts for your car, when there’s so much choice out there? The good news is, the biggest names in the industry grouped together over a decade ago to form the Performance Automotive Aftermarket Association. An Avenger’s style collective of the great and the good that are here to see you right.

All of the brands that form this trade association will be marking ALL products that will get you the right side of the law with their distinctive SMART mark, going forward. This stands for Safe Modification And Responsible Tuning – and if you see it on a product you know you can fit it to your motor with impunity. As long as you’re driving sensibly and within the speed limit, those lovely police officers are going to leave you well alone. And as for your MoT tester? They’re going to greet you like a long lost relative.

It’s fair to say that the eyes of the legislators are on our scene – and it’s probably a good time to play along. If we do, they’ll probably leave us alone to concentrate on problems elsewhere. Or, if we continue to try their patience, we’ll end up like Switzerland… where you have to fill out forms in triplicate just to add a bumper sticker… and nobody wants that.

Head over to and you’ll be able to find the companies that have all signed up to a DVSA-friendly code-of-conduct, and they’ll also be able to sell you SMART-marked products that will make your insurance company love you even more than your local 5-0 will. It really is easier than you think to future-proof that ride – and buying and fitting the right gear is ALWAYS cheaper than the points and fine in the long run.

Words: Paul Cowland.