All generations and engines together · 7,081 MOT tests in the 2025 data · typical mileage at age 7: 31k
One of the best coupés and convertibles for its age, but about average per mile driven. Watch suspension and brakes. One to judge on its mileage rather than its age, and worth it only if its MOT history has no repeating suspension advisories.
Split by first-registration year. Cars registered in a changeover year can belong to either generation.
Owner folklore from forums and the motoring press, with how well each report stands up. Most of it never shows up in an MOT, which is why this section exists at all.
The R230 (2001-2011) and some R231 models use Active Body Control, a hydraulic active suspension instead of normal springs and dampers. Accumulators rupture, struts weep fluid and the pump wears out, usually from around 60-80k miles or once the car is into its second decade, throwing an ABC warning light and leaving the ride rock-hard or lopsided. The measured MOT data backs this up directly: suspension is the standout failure category for this model, and the ABC system is the specific hardware forums point to. A single strut runs from around £850 (remanufactured) to £1,600-1,800 (new OEM), so a car needing more than one gets expensive fast, and some owners report £9,000+ bills to sort the whole system.
Early R230 cars (roughly 2001-2005) used Sensotronic Brake Control, a drive-by-wire braking system with a conventional hydraulic backup. The pump has a finite working life and wear brings up a "Brakes Defective, Stop Vehicle" warning with a heavy, spongy pedal. Mercedes recalled hundreds of thousands of SBC-equipped cars in 2004-2005 over a wiring/ground fault, and separately extended the SBC warranty to 10 years/unlimited miles, which tells you how seriously the fault was taken. Outside that warranty window, a pump or hydraulic unit replacement is a four-figure dealer bill.
The retractable metal roof on R230 and R231 cars relies on hydraulic cylinders, motors and multiple microswitches to fold itself away. Owners report leaking hydraulic hoses and cylinders, a roof that stalls mid-cycle, CAN-bus communication faults and worn microswitches, appearing anywhere from 8 years old onward as seals and hydraulics age. Specialist roof shops quote around £500-600 for straightforward electrical/mechanical faults, rising well beyond that for cylinder or frame replacement. No manufacturer campaign covers this; it is treated as wear and tear.
R129 SLs built in the 1993-1995 model years used a wiring insulation that was found to crack and flake with heat and age, particularly on the engine harness, injector and throttle body looms. This causes intermittent shorts, warning lights and, in the worst reported cases, engine bay fires. Mercedes never ran an official recall for it despite the issue being raised repeatedly, so it is down to the owner to inspect and re-sleeve or replace affected harness sections, typically a few hundred pounds in specialist labour if caught early.
SL500/550 and SL63 AMG cars from the R231 generation use the M278 or M157 twin-turbo V8, engines that have a well-documented history of camshaft, timing chain and oil-consumption problems at higher mileages in other Mercedes models carrying the same units. R231 owner forums have not reported the same scale of failures yet, likely reflecting lower mileages on these cars, but the underlying engine risk is the same. Does not apply to the four and six-cylinder SL350/400/450 cars.
Owners of the R231 generation report the car as unusually trouble-free by SL standards, with the vario roof, occasional auxiliary battery replacement and minor items like seat massage motor failure being the main gripes. This generation does not show the ABC or SBC problems that dominate R230 ownership, since later cars moved away from Sensotronic brakes and improved the active suspension hardware.
Ranked from this model’s own MOT record, then from what owners report.
Saveable checklistThe physical checks its own defect data says are worth your time, most telling first.
These judge the seller’s upkeep rather than the model, and they are where the haggling money is.
The physical checks its own defect data says are worth your time, most telling first.
These judge the seller’s upkeep rather than the model, and they are where the haggling money is.
Drawn from the reports above rather than the MOT data. These are the model-specific ones.
Computed from DVSA MOT results, all of Great Britain, 2025. Nothing here is opinion.
Share of tests where each item was recorded. The dark tick is the class average across all tracked models; bars are scaled within each group.
The rows that judge the model rather than its keeper. 2,406 tests in this band.
Tyres, pads and stone chips say more about how the car was driven and maintained than about how it was built.
Same segment (Coupés, convertibles & GT), best MOT record first. Compare before you shortlist.