What are the most common problems with a Smart Fortwo?

Known faults on the Smart Fortwo include roof leaks (cabriolet). At MOT, rigid brake pipes and exhaust emissions (catalyst) are flagged more often than on other cars the same age.

What should I ask the seller before buying a used Smart Fortwo?

Any recent work on the rigid brake pipes? (Flagged at MOT 2.9× as often on the Smart Fortwo as on other cars the same age.) Any recent work on the exhaust emissions (catalyst)? (Flagged at MOT 6.5× as often on the Smart Fortwo as on other cars the same age.) Any recent work on the braking performance? (Flagged at MOT 2.2× as often on the Smart Fortwo as on other cars the same age.) Can I see the service history and receipts for any big jobs?

Used car guide · 2002–2024

Smart Fortwo common problems and MOT failures

What goes wrong on a used Smart Fortwo, year by year: known faults from UK buying guides, the parts flagged at MOT more than on other cars (from 133,485 MOTs done during 2023–2025), and what to check before you buy one.

The 2020 Smart Fortwo

Too few Smart Fortwo cars first registered in 2020 had an MOT during 2025 for reliable MOT figures. There are no known faults on record for this year in the UK buying guides we use, so the rest of this page covers the Smart Fortwo as a whole.

544on the UK register at the end of 2025

Petrolmost common fuel (also electric)

What to check on a 2020 car

MOT history
Check the reg below: its MOT history shows what has been failed or advised, and whether the mileage adds up.
Service history
Look for regular servicing and receipts for big jobs like a cambelt or clutch.
Finance and write-offs
MOT records don’t show outstanding finance or insurance write-offs. A history check does.
Test drive
Listen for knocks over bumps, check every warning light goes out, and make sure the gears and brakes feel right.

Other years

Most years have their own guide. The year is when the car was first registered (it’s on the logbook, or check the reg below).

2024 2023 2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002

What usually goes wrong with a Smart Fortwo?

Known faults reported by owners, mechanics and UK buying guides, in our own words. Most apply to certain years or engines only, so check which the car has.

Roof leaks (cabriolet)
Cars registered 2007–2014 · Cabriolet
Cabriolets have had leaks and water damage from the roof.

At the viewing: On a cabriolet, check the roof seals and feel the carpets and seats for damp.

Source: RAC: smart fortwo (2007-2014) used car review

Common Smart Fortwo MOT failures to check

Parts flagged at MOT well above the usual rate for cars the same age, for each fuel on its own. From the DVSA’s results for every MOT done in Great Britain during 2023–2025.

Petrol

Rigid brake pipes
up to 3.2× usual

Stands out on cars registered in 2009, 2012 and 2013.

Rough price £100–£400 our estimate

At the viewing: Ask to see underneath, or check the MOT advisories: corroded brake or fuel pipes get worse every year and fail the MOT when they do.
Braking performance
up to 2.1× usual

Stands out on cars registered in 2011, 2012 and 2013.

Rough price £100–£350 our estimate

At the viewing: On a quiet road, brake firmly from about 30mph. The car should stop straight without pulling.

Diesel

Rigid brake pipes
up to 4.7× usual

Stands out on cars registered in 2009, 2010 and 2013.

Rough price £100–£400 our estimate

At the viewing: Ask to see underneath, or check the MOT advisories: corroded brake or fuel pipes get worse every year and fail the MOT when they do.

Smart Fortwo MOT pass rate by year

Of the years since 2005 with plenty of MOT tests, the 2012 Smart Fortwo did best (72% passed first time, 8 points above all 2012 cars) and the 2005 did worst (56%, 1 point below all 2005 cars). Older cars fail more, so compare each year with all cars registered the same year.

Year	Pass first time	All cars that year	MOT tests
2019	87%	85% +2	5,575
2018	84%	83% +1	9,966
2017	81%	80% +1	14,234
2016	79%	77% +2	16,973
2015	77%	74% +3	6,533
2014	77%	70% +7	10,991
2013	72%	67% +5	2,713
2012	72%	64% +8	5,472
2011	68%	62% +6	9,133
2010	65%	60% +5	13,296
2009	63%	59% +4	14,337
2008	62%	57% +5	11,719
2007	61%	57% +4	5,628
2006	59%	56% +3	2,481
2005	56%	57% -1	1,991
2004	60%	57% +3	1,759
2003	59%	57% +2	456 (small sample)
2002	59%	58% +1	228 (small sample)

Questions to ask the seller before buying a Smart Fortwo

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

Any recent work on the rigid brake pipes? (Flagged at MOT 2.9× as often on the Smart Fortwo as on other cars the same age.)
Any recent work on the exhaust emissions (catalyst)? (Flagged at MOT 6.5× as often on the Smart Fortwo as on other cars the same age.)
Any recent work on the braking performance? (Flagged at MOT 2.2× as often on the Smart Fortwo as on other cars the same age.)
Can I see the service history and receipts for any big jobs?

Looking at a Smart Fortwo?

Check the actual car: its own MOT history, whether it already shows these weak spots and what to ask the seller. Free, no sign-up.

Where this comes from: MOT figures are the DVSA’s anonymised results for every MOT test done in Great Britain during 2023–2025, grouped by the year each car was first registered. How many are on the road is from the Department for Transport’s vehicle licensing statistics. Known faults are from UK buying guides, in our own words, with links. How we score