Smart (mcc) Roadster MOT Failures
An analysis of 20,657 real DVSA MOT tests on the Smart (mcc) Roadster — what fails, how often, and how that compares to every other car on UK roads. Generations covered: R452 (2003–2007).
Where the Smart (mcc) Roadster fails its MOT
The single biggest MOT failure point on the Smart (mcc) Roadster is light unit fault — this model is 48 times more likely to fail on this item than the average car on UK roads. That makes it a significant weak point for anyone buying or owning this model. Across 20,657 MOT tests, 14.27% of all Smart (mcc) Roadster tests recorded this as a failure.
Lighting faults are usually straightforward to fix (bulbs, connectors, earth points) but can indicate deeper wiring issues on older cars. Check all lights including fog lamps, number plate lights, and dashboard warning lights.
Other notable weak points include abs fault (17x the fleet average), brake hoses perished or damaged (15x the fleet average), wheel badly distorted or wear between wheel and... (13x the fleet average), and wheel bearings worn (23x the fleet average). These ratios compare the Smart (mcc) Roadster's failure rate on each item against the national average for all cars tested — a ratio of 10x means this model fails ten times more often than a typical car.
The failures span 5 categories: Lights & Electrics, Suspension, Brakes, Wheels, Steering. If you're inspecting a Smart (mcc) Roadster before purchase, these are the areas to focus on — and if any have been flagged as advisories on a previous MOT, they're likely to become failures in the near future.
How failures change with mileage
The Smart (mcc) Roadster's weak points shift as the car covers more miles. Understanding these patterns helps you know what to expect — and what to budget for — at each stage of ownership.
Under 60,000 miles
At this mileage, most failures are either design-related or caused by age rather than wear. Components like bushes and drop links may not have been replaced yet, and original-fit parts can deteriorate even on low-mileage cars that spend a lot of time sitting.
For the Smart (mcc) Roadster specifically, the DVSA data shows the most common failures at this mileage are light unit fault (48x the average) and electrical wiring fault (26x). wheel bearings worn (23x) and suspension component damaged or corroded (22x) also appear frequently.
60,000 to 100,000 miles
This is where routine wear items start to show up. Brake components, tyres, and exhaust parts have done serious work by this point. Cars that have been well serviced will show fewer of these failures — this mileage band is where good maintenance really separates the well-kept from the neglected.
For the Smart (mcc) Roadster specifically, the DVSA data shows the most common failures at this mileage are light unit fault (20x the average) and abs fault (15x). electrical wiring fault (14x) and stop lamp with a multiple light source up to 1/... (13x) also appear frequently.
Over 100,000 miles
High-mileage cars accumulate failures across multiple systems. The key question isn't whether things will need doing — they will — but whether the car has been maintained well enough to keep on top of them. Look for a consistent service history and recent MOT passes with minimal advisories.
For the Smart (mcc) Roadster specifically, the DVSA data shows the most common failures at this mileage are light unit fault (16x the average) and abs fault (12x). suspension pin, bush or joint worn (12x) and wheel bearings worn (7.5x) also appear frequently.
Known issues beyond the MOT
An MOT only tests roadworthiness at a single point in time — it won't catch developing faults, intermittent problems, or issues that haven't yet reached the failure threshold. These are the issues that Smart (mcc) Roadster specialists and owners flag most frequently, drawn from manufacturer technical bulletins, workshop data, and verified owner reports.
Brake hose deterioration (R452) Dangerous
The Roadster's flexible brake hoses are exposed to road debris and weather due to the car's low stance and minimal body protection. Affects R452; typical independent garage repair cost is £150–£300.
Brake pipe corrosion (R452) Dangerous
The Roadster's exposed brake pipe routing and minimal underbody protection make the metal brake lines particularly vulnerable to corrosion. Affects R452; typical independent garage repair cost is £200–£500.
Suspension component corrosion and damage (R452) Major
The Roadster's exposed chassis design and low ground clearance make suspension components particularly vulnerable to corrosion and impact damage. Affects R452; typical independent garage repair cost is £300–£800.
Shock absorber bush excessive wear (R452) Major
The Roadster's firm sports suspension and limited wheelbase place high loads on shock absorber mounting bushes. Affects R452; typical independent garage repair cost is £200–£400.
For the complete picture — including repair costs across independent, specialist, and dealer garages — see the full Smart (mcc) Roadster common problems breakdown.
What to check before buying a Smart (mcc) Roadster
Based on the MOT failure data and known issues above, here's what to prioritise when inspecting a Smart (mcc) Roadster:
Lights & Electrics — check for light unit fault, electrical wiring fault. Suspension — check for abs fault, wheel bearings worn, suspension component damaged or corroded. Brakes — check for brake hoses perished or damaged. Wheels — check for wheel badly distorted or wear between wheel and....
Beyond the MOT items, ask specifically about brake hose deterioration and brake pipe corrosion. These won't show up on a standard MOT but can be expensive to fix — repairs start from £150. A specialist pre-purchase inspection is worth the investment on this model.
Always check the car's full MOT history for patterns — recurring advisories often become failures within 12 months. And verify the service history to confirm maintenance has been kept up to schedule. Enter any reg into our free car check to see the complete picture.
Looking at a specific Smart (mcc) Roadster?
Enter the reg to see its full MOT history, mileage records, write-off status, and finance checks.
Smart (mcc) Roadster MOT FAQs
What are the most common MOT failures on a Smart (mcc) Roadster?
Based on 20,657 DVSA MOT tests, the most common failure is light unit fault — at 48x the national fleet average. Other frequent failures include abs fault and brake hoses perished or damaged.
Is the Smart (mcc) Roadster reliable based on MOT data?
The Smart (mcc) Roadster has 12 MOT failure categories above the fleet average. Specialists also flag brake hose deterioration as a concern. A pre-purchase inspection and service history check are recommended.
What MOT failures should I expect at high mileage?
Above 100,000 miles, the Smart (mcc) Roadster most commonly fails on light unit fault and abs fault. Under 60,000 miles, the main issues are light unit fault and electrical wiring fault.
How do I check a Smart (mcc) Roadster's MOT history?
Enter the registration number into our free car check above. You'll see every MOT test result, advisories and failures, mileage readings, write-off status, and finance checks.
MOT failure data sourced from DVSA bulk test records via data.gov.uk. Ratios compare this model's failure rate against the national fleet average. Known issues sourced from manufacturer bulletins, specialist workshops, and verified owner reports.