Generations
450 — First Generation City Cabriolet
1999–2012
0.6L three-cylinder
Top issues to watch for
The most serious Smart (mcc) City Cabriolet problems ranked by severity. We track 5 known issues — here are the ones you need to know about first.
Major
Brake hose deterioration (450)
The flexible brake hoses on Smart City Cabriolets deteriorate at a much higher rate than the fleet average, with failures occurring across all mileage bands. The short wheelbase and exposed position of the hoses make them prone to damage from road debris and environmental factors. MOT data shows this model fails at 131 times the fleet average for brake hose defects, with the highest failure rate between 20,000-40,000 miles.
What happens if ignoredFailed brake hoses can result in complete loss of braking on one or more wheels, creating a serious safety hazard. Deteriorated hoses may burst under emergency braking conditions. All four hoses typically require replacement together, with labour costs increased by the need to bleed the brake system.
Independent garage
£200–£350
Specialist
£250–£400
Main dealer
£350–£500
Parts only
£80–£150
Major
Wheel bearing wear (450)
Wheel bearings on Smart City Cabriolets wear at a significantly higher rate than the fleet average, with failures occurring 8.4 times more frequently than typical cars. The lightweight construction combined with relatively large wheels for the vehicle size places higher loads on the bearings. Failed bearings create safety risks and must be addressed promptly.
What happens if ignoredFailed wheel bearings create a serious safety hazard as they can cause wheel detachment in extreme cases. Worn bearings cause uneven tyre wear, poor handling, and increased braking distances. The car should not be driven with severely worn bearings.
Independent garage
£150–£250
Specialist
£180–£300
Main dealer
£250–£400
Parts only
£60–£120
Minor
Shock absorber bush wear (450)
The rubber bushes that mount the shock absorbers to the chassis wear prematurely on Smart City Cabriolets, failing at 25.6 times the fleet average. The lightweight construction and hard suspension tuning accelerate bush deterioration. This affects ride quality and handling precision, with the problem typically appearing from 20,000 miles onwards.
What happens if ignoredWorn shock absorber bushes reduce ride comfort and handling precision. In severe cases, completely failed bushes can allow the shock absorber to move excessively, potentially damaging other suspension components. The car remains safe to drive but handling and comfort are compromised.
Independent garage
£120–£200
Specialist
£150–£250
Main dealer
£200–£320
Parts only
£40–£80
Minor
Lambda sensor failure (450)
The lambda (oxygen) sensors in Smart City Cabriolets fail at The three-cylinder engine's operating characteristics and the sensor's exposed position in the exhaust system contribute to premature failure. Failed sensors cause poor emissions performance, increased fuel consumption, and potential MOT failure.
What happens if ignoredFailed lambda sensors cause increased fuel consumption, poor emissions performance leading to MOT failure, and potential long-term damage to the catalytic converter. The car remains driveable but will not meet emissions standards and may experience reduced performance.
Independent garage
£80–£150
Specialist
£100–£180
Main dealer
£150–£250
Parts only
£50–£120
1 more known issues tracked
Including wear items, electrical niggles, and generation-specific problems.
MOT failure hotspots
Based on DVSA MOT test data. These are the items where the Smart (mcc) City Cabriolet fails at a significantly higher rate than the average car.
Brake hoses perished or damaged
Brakes · 20-40k miles
MOT failure rate: 131x the fleet average
Sample: 217 tests
Light unit fault
Lights & Electrics · 20-40k miles
MOT failure rate: 86x the fleet average
Sample: 564 tests
Fuel system leaking, or missing or ineffective ...
Bodywork · 40-60k miles
MOT failure rate: 34x the fleet average
Sample: 759 tests
Cable damaged or knotted
Brakes · 40-60k miles
MOT failure rate: 33x the fleet average
Sample: 835 tests
Emissions failure
Exhaust & Emissions · 60-80k miles
MOT failure rate: 32x the fleet average
Sample: 723 tests
Stop lamp with a multiple light source up to 1/...
Lights & Electrics · 40-60k miles
MOT failure rate: 31x the fleet average
Sample: 1,189 tests
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Related
- Smart (mcc) City Cabriolet buyer's guide
- Smart (mcc) City Cabriolet service history check
- Smart (mcc) City Cabriolet service schedule & costs
- Smart (mcc) City Cabriolet MOT failure rates
- Buying a car without service history
- Smart (mcc) City Cabriolet car check £7.49
- Free car faults check
- Free MOT failure rate check
- Free car check
Smart (mcc) City Cabriolet reliability FAQs
What are the most common problems with the Smart (mcc) City Cabriolet?
The Smart (mcc) City Cabriolet has 5 known issues across 2 severity levels. The most common problems relate to Brake hose deterioration (450) and Wheel bearing wear (450).
Is the Smart (mcc) City Cabriolet reliable?
The Smart (mcc) City Cabriolet has 0 dangerous and 2 major known issues. No dangerous issues are tracked, which is a positive sign.
How much does it cost to fix Smart (mcc) City Cabriolet problems?
Repair costs range widely. The most significant issue (Brake hose deterioration (450)) costs £200–£350 at an independent garage. Minor issues can be under £200. Always get a full inspection before buying.