– Trieste, Italy

Despite an internet’s worth of images showing happy people driving against backdrops of sunsets and seas, dropping the top on a convertible doesn’t guarantee perfect weather. Such was the case last week as I nestled into the driver’s seat of a 2017 Mercedes-Benz C300 Cabriolet, the pitter-patter of rain audible on the three-layer cloth top overhead. I’d flown all the way to Italy to test Merc’s latest four-seat convertible, yet the clouds refused to break. Thanks for nothing, Mother Nature.

Which brings me to a sad point of reality: Most of the time, luxury convertibles like this one are driven with their tops up. Whether it be because of cold climates, rainy days, or fussy owners who won’t put the top down unless the temperature outside is just right, a lot of convertible cars rarely enjoy long stints of top-down motoring. And while I wasn’t expecting to primarily test the C300 Cabrio in this top-up setting (the accompanying photos were taken during the 15-minute window when it finally stopped raining, by the way), I learned that Merc’s newest Cabriolet offers a myriad of pleasantries and charms that are accessible regardless of roof position. After all, it’s still a C-Class.

The C300’s folding cloth top takes just 20 seconds to retract, and can be operated at speeds up to 31 mph.

From a design standpoint, the topless C-Class retains the model’s elegant shape and handsome styling, though the lack of a sloping roofline reduces visual interest at the...