Rust and MOTs: Why Corrosion Can Mean a Fail – and How to Stop It

28 gen 2026

 

You Look After Your Car – But Rust Might Still Catch You Out at MOT Time

You’re not alone if you've had that sinking feeling: the MOT report comes back and it's a fail – not because of anything obvious, but because of corrosion underneath.

It’s more common than people think.

Rust doesn’t always show up until someone gets under the car with a torch and a lever – and unfortunately, that’s exactly what an MOT tester will do. And if that rust is near a structural or suspension mounting point, it can mean an automatic failure.


🎥 Watch: How Rust Causes MOT Fails


Why Underbody Rust Matters at MOT Time

When it comes to MOTs, surface rust isn’t always the issue – it’s where the rust is and how deep it goes.

MOT testers look closely at:

  • Suspension mounting points

  • Brake lines

  • Chassis rails and sills

  • Seatbelt anchor points

  • Subframes and crossmembers

If corrosion is judged to weaken the structure in any of these areas, it's often marked as a major defect – meaning an instant fail. Worse still, the repair can be expensive: cutting, welding, and re-coating, often at short notice.


"My Car Failed Its MOT Due to Rust – What Now?"

If your car’s failed due to rust, it doesn’t always mean it’s a write-off. But it does mean action is needed.

Often it’s not just about fixing the damage, but stopping it coming back.

That’s where Lanoguard can help.


Lanoguard: MOT Rust Protection That Actually Works

Lanoguard is used by owners across the UK to protect their cars from underbody corrosion. It's a spray-on, eco-safe rust protection system that:

  • Stops existing rust in its tracks

  • Seals and repels water, salt, and road grime

  • Creates a flexible, moisture-blocking barrier

  • Can be applied at home in an afternoon

It’s not a miracle cure – but it does work, and many customers tell us it’s helped their vehicles pass MOTs they’d previously failed due to corrosion.


💬 Real Owners, Real Results


🛠️ Want to Prevent Rust Before It Gets Expensive?

Lanoguard is designed to be easy to apply at home, with a kit that includes everything you need – plus optional accessories to make the job even easier.

It’s about being proactive, not reactive.

And if you’re under your car anyway doing pre-MOT checks or servicing – there’s no better time to apply it.


What Next?

  • ✅ Check your car for rust around MOT-critical areas

  • ✅ Watch the video above for what to look for

  • ✅ Protect your vehicle with Lanoguard to help avoid a future fail


🧰 Products to Help You Do the Job Properly


It’s Your Car – Let’s Keep It On the Road

MOT rust failures can sneak up on you. But with the right prevention, they don’t have to.

Take a look under your vehicle, watch the video, and if you see any signs of rust – now’s the time to act.