Used buying guide: Mercedes Benz SL500 R129

For 1994, the 500 SL was renamed the SL 500; a 1995 facelift brought revised front wings and bumpers and the addition of side airbags; and 1996 ushered in options including a sunroof, rain-sensing wipers, front occupant detection and a Sport pack with bespoke styling and 18in wheels. 

A second facelift in 1998 added a new steering wheel, curved taillights, 17in rims as standard, nappa leather seats and body-coloured door handles. More important, the V8 was swapped from the 32-valve dualcam M119 unit to the 24-valve singlecam M113, which reduced power to 298bhp but is regarded by many as the superior engine, courtesy of its lightness and enhanced efficiency. 

The R129 wasn’t short on special editions, either. The ultra-exclusive Mille Miglia edition was launched in 1995 to mark the 40th anniversary of Sir Stirling Moss’s iconic 1955 race win, for example, and 100 Silver Arrow Editions were built in 2002 to honour Mercedes’ 1930s grand prix racers. But both are uber-rare on the used market, so don’t hold out for one.

An expert’s view

Bruce Greetham, The SL Shop: “The appeal to most new buyers of the R129 SL 500 model is the easy roof operation with a flick of a button – the feeling of something expensive and good quality – combined with the smooth performance of its V8 engine.

"The linear power delivery is seamless throughout the gears. It will be a car you will drive less often but is more special. Most feel it’s the only model worth having, courtesy of its V8. As for which car ticks all the right boxes, it’s mainly determined by colour, condition, history and mileage.” 

Buyer beware… 

Engine: The oil-supply tubes to the camshafts can blow, causing heavy tapping. The wiring looms on early examples can degrade, causing an engine misfire and other electrical problems that are expensive to fix and sometimes lead to wider ignition problems. 

Interior: Trim pieces can wear and the leather (including the nappa in later cars) might need replacing. Make sure all the gadgets work too, including the odometer, heater panel display, electrically adjustable seats and roof release. Also check the roll bar raises properly in case it’s ever needed. 

Suspension: The SL 500 tipped the scales at 1880kg, so check the suspension top mounts, dampers and springs for signs of a life hard lived. Be wary of any original components. 

Roof: The hydraulic roof mechanism is prone to locking up, but it’s an easy fix if taken to a proper mechanic, while damp in wetter climes can corrode the electrics. The roof controller module can also fail (it’s expensive to replace) and the hydraulic rams for the roof mechanism can leak onto the header rail and prevent proper operation. 

Electronics: Faulty air-conditioning systems and heated seats are expensive to put right so can fall by the wayside. Buy the best replacement parts you can afford and use all devices regularly to exercise all the moving parts. The anti-lock brakes and traction control can sometimes fail and are very difficult to trace, even with diagnostics. 

Also worth knowing

The SL Shop says buyers should look out for design specifics when identifying post-1998 cars, which feature chrome rings around the dials and a four-spoke steering wheel with a chrome star in the airbag centre. Beware inconsistencies and ask for any missing parts.