Used Mercedes-Benz SL-Class R129 review and buying guide (1989 to 2001): which one to buy and what to check

Which used Mercedes-Benz SL-Class R129 should you buy?

A six-cylinder SL-Class R129 is the sensible one to buy, whether that's a 280, a 300 or a 320. There are plenty of R129s in the trade with a murky story behind them, so an original right-hand-drive car that can show its paperwork is the one to chase.

Don't touch a car that's been converted from left-hand drive, one that turns out to be a clone, or one built for a Far East export order that was cancelled. All three turn up in the trade, so match the documents to the car before you agree a deal, and leave it if the two don't line up.

Which SL-Class R129 engines and gearboxes are the safe choices?

The six-cylinder 280, 300 and 320 are the safe choices, and the 300 came in both 12-valve and 24-valve forms. Whichever engine you pick, it wants fully synthetic oil changed every 3,000 miles, so ask for stamps or receipts that show it's had those short intervals rather than taking a seller's word for it.

If you want more than six cylinders, there's the 500 V8, the 600 V12 and the AMG SL60 V8, and the SL60's the one that handles better than the 600. Every R129 feels soft and heavy through bends, though, so don't expect any of them to turn it into a sharp drive.

The automatic gearbox can change gear in the middle of a bend when you'd rather it held on. It's a trait of the R129's autobox rather than a fault on one car, so take it through a few corners on the test drive and decide whether it's something you can live with every day.

What should you check when viewing a used SL-Class R129?

Lift the carpets in both front footwells and feel for damp, because the ventilation plenum behind the bulkhead can rust through and let a lot of water in. Fixing it means pulling out the dashboard and the heater, cutting out the rot, welding in fresh metal and sealing it, so a wet footwell isn't a small job.

Don't view one with the hardtop fitted unless the seller will lift it off, because you need to see the soft top working and check its fabric for tears and mould. Taking the hardtop off needs two people. With it off, look for rust low down on its rear sides, and go over the body for signs of crash repair.

Run the air conditioning and make sure it's blowing cold. Ask for proof that the airbag recall was done, which replaced bags whose trigger could corrode in damp air and set them off, and that the rear silencer's been swapped for a stainless steel one under the exhaust recall, which stopped the pipe breaking away from the silencer and scorching the back of the car.

Paste the advert into the free check and it runs these against the listing, the MOT history and the DVLA record before you travel.