Mercedes SL 350 (R320) | Shed of the Week

Probably the best looking SL of the 21st century is available for shed money - should you take the plunge?

By Tony Middlehurst / Friday, 7 August 2026 / Loading comments

If Shed had a pound for every ‘project’ he’s been offered (and rejected) over the years, he’d have enough money to take the postmistress to the Maldives. This bargain basement ‘project’ R230 SL 350 is different. It’s got him seriously scratching his stubble.

The R230 SL landed in 2002 and remained in Mercedes brochures for more than ten years. Many believed it to be the best-looking SL. Some still believe that. At £2,000, this car is being offered at well below normal retail under the tempting project header. It was registered in 2006, four years into the production run, which was enough time for some of the (many) early issues to have been sorted, but some have come back to haunt it.

Like what? Well, the R230 was Mercedes’s first attempt at a folding metal hardtop and as you might surmise from M-B’s bad reputation for electronickery at this time they weren’t problem-free. Our shed’s roof isn’t working. Specialists Hoodtech list about twenty ways in which it could go wrong and quote an average cost of repair of £495-£595 including VAT, but if you’re very lucky it might just be a dodgy consumer battery, the second one in the SL’s boot that’s responsible for ancillaries including the heated seats and the roof. You should always keep it on a trickle charger to maintain its minty freshness. Like Mrs Shed, it should never be jumped.

Once you’ve got the roof working, cheaply or expensively, it’s worth shoving some Gummi Pflege or Liqui Moly Rubber Care on all the seals. There’ll still be a degree of creaking in the cabin but there should also be less water getting in. Water can get into the boot too, often via a poorly fitted or cracked bootlid light. Rust will certainly attack the wheel arches of neglected R230s, but so far at least there have been no appearances of the ‘c’ word on the MOT history.

All SL 500s had roll-reducing Active Body Control as standard, but Benz’s electronically controlled hydraulic system was only an option on the SL 350. You’ll be hoping that the box wasn’t ticked for our shed because ABC is notorious for failing in a pricey way. There’s no mention of ABC on the ad so we could be all right there.

When the M112 engine appeared in 1997 it was Mercedes’s first petrol-powered V6. A twin-spark, single cam, three valves per cylinder design with a vibe-dousing balance shaft, the M112 came in various capacities from 2.4 litres to the biggest 3.7 (a bored out version of the 3.2) that powers our shed. It’s not the 2006 facelift motor with 268hp, but it’s still healthy enough with 245hp and 258lb ft to generate a raspy 0-60mph time in the low sevens.

The M112 has proved to be a solid and reliable unit. This one has had an oil leak since 2021, most likely from one or both of the rocker covers. These leaks are easy to put right, but replacing dead hydraulic pumps, hoses and accumulators isn’t the work of a moment. ECU issues can queer up the transmission and the PSE central locking vacuum pump. Our car has non-functioning central locking. Dealers will try to hit you up for £1,000 or so to replace the complete pump, but more often than not it’s just the pump’s graphite impeller that needs replacing. You can pick one of those up off tinternet for under £30.

The big downside of an older, high-CO2-emitting (276g/km) engine like the M112 is the tax hit it takes in the UK. Our shed was first registered on 31 March 2006. If it had been registered eight days earlier it would have sneaked into the mysterious VED Band K* at £445 a year. As it stands though, the bill will be £790pa - gah.

Some might add ‘non-functioning roof’ to ‘airbag warning light’ and come to ‘crashed’. Obviously spending a few quid on a history check would be a wise investment, then you’ve got three months’ worth of MOT to get the airbag sorted. If it’s just the module that needs resetting, you could get away with a bill of well under £100. The interior is crying out for some restorative elbow grease on the leather and wood bits, but unless the wheel has got Novichok on the rim that isn’t going to worry the MOT tester so you can tackle that in your own sweet time.

When this car was new it would have cost £63,000, which is £118,000 in today’s money. This shed will cost you £2,000, which is £2,000 in today’s money, or about six PCP rental instalments on a Ford Focus. If you’re ready to take up the vendor’s ‘project’ challenge and you get lucky with the fault fixing, you could end up with a right result here.

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