1968 Mercedes-Benz 300SE Cabriolet

This 1968 300SE Cabriolet sold for $50,139, including buyer’s premium, at the Bonhams Monaco auction held on May 15, 2004.

In the 1960s, the 300SE was Daimler-Benz’s most luxurious and expensive car, other than the built-for-kings 600 series. Based on the modern 220S body, Mercedes’ top-of-the-line model was available in sedan, coupe and convertible body styles, fitted with a version of the fuel-injected aluminum 3-liter six originally designed for the 300SL roadster, which made 185 hp and 205 lb-ft of torque. Top speed was between 115-125 mph, depending on the model and gearing. While the sedans featured the controversial “fin-back” styling, the coupes and convertibles had more-modern rounded rear fenders, which partly contributes to their greater popularity today.

Knowledgeable rally enthusiasts know the 300SE to be rugged and reliable, with a history of successful competition. Works 220SE coupes swept the podium at the Monte Carlo Rally in 1960 and a 1964 300SE coupe won the six-cylinder touring class in the 2,200-mile revival of the La Carerra Panamericana, the famous Mexican road race, in 2002. A strong unibody chassis and supple, height-adjustable air suspension makes for not only a well-balanced rally car, but also an excellent modern freeway cruiser or a tireless and comfortable performer for less demanding vintage events.

Originally designed with front discs and rear drums inside 13-inch wheels, the 300SE was fitted with four-wheel disc brakes in 1963 and 14-inch wheels for 1966. The fuel-injection system was upgraded in 1964, boosting output by 10 hp, and an oiling problem with the number seven bearing was addressed. Mercedes made all of these changes on a continuing basis rather than starting with an exact chassis number.

Things to watch for on these cars include problems with the air suspension, as its pump is coupled to the power steering pump and does not tolerate air in the lines. As these systems are expensive to repair, some cars have been converted to coil springs.

Automatic transmissions are vacuum-controlled, so a car needing carburetor work may not shift correctly. Even a properly working automatic transmission won’t be particularly impressive, especially to those accustomed to the magic of modern electronically controlled gearboxes.

U.S.-spec cars can be identified by two-part headlamps, with a separate parking light. European cars have both contained in a single unit.

Mercedes is almost alone among European car builders in its pursuit of luxurious, high performance, four-passenger convertibles. The 300SE cabriolets were a huge step up from their 220SEb brethren, and although they still had manually operated tops, the tops themselves were of high-quality padded canvas. When properly fit, a 300SE cab with the top up is nearly as quiet as a coupe.

Be wary of coupes that have been chopped into convertibles, as there are a number of these floating around. A real convertible will have a three-inch gap between the chrome molding where the top folds into the body, and the trunk lid. Chopped cars tend to have the body opening for the convertible top meeting up with the trunk-lid opening. More important, check the VIN. All 300SEs have a VIN prefix of 112, and convertibles follow that with .023, so a factory-built convertible will read 112.023. Further, if the VIN is 112.023-10, the car was originally equipped with a manual transmission, -12 if automatic.

Partially hand-built, only 708 300SE convertibles were produced over all model years, making them much more rare than later SEs. The chrome-plated brass trim on the wheel arches and on the sides of the cars is unique to the 300SE, although many enthusiastic owners have added this feature to their 220/250/280SEs.

300SEs, partly due to their old-fashioned tall grilles, have always been a cult car, the forgotten buck-toothed stepsister to the more popular, low-grille, V8-equipped 280SE 3.5 convertible that followed. The SCM Price Guide lists values for 300SE Cabs between $35,00-$55,000, versus $60,000-$80,000 for the 3.5. But marque expert and fellow SCM contributor Alex Dearborn contends that a properly set up 300SE is a nicer car to drive, with more power than the six-cylinder 280SE, and a better suspension with less weight on the front wheels than the 3.5.

The 1968 Cabriolet pictured here, in the always-popular silver/navy blue color combination and with full service history, was bought for about 10 percent below the high SCM Price Guide range. With the 300SE’s exclusivity-fewer were made than the 280SE 3.5, or even the famed Gullwing-we expect the market for these cars to continue appreciating, and values are already up some 13 percent from a year ago. Further, if you are looking for an open four-seater for classic events, one that is both relatively affordable and can cruise at high speeds all day long, the 300SE is a perfect choice.

For a nice example of a classic Mercedes body style in a true four-place open car, this one was well bought.-Alex Finigan (with additional information by Alex Dearborn)