Based on the long-wheelbase Mercedes-Benz W126 S-Class (specifically the 500 SEL), the Tiara was essentially a bespoke re-bodying of the German sedan. Only three units were ever built, making it one of the rarest luxury vehicles of its era.

Available with the 3.8L V8 (204 hp) and the 5.0L V8 (231 hp).

The 5.0L version could reach a top speed of roughly 235 km/h.

At its 1982 launch, it cost 172,000 Swiss Francs, which was twice the price of the equivalent Mercedes-Benz S-Class at the time.

Redesigned with a vertical chrome grille and four round headlights, similar to the older Monteverdi High Speed 375 series.

While the doors, glass, and roof remained original Mercedes parts, Monteverdi heavily modified the front and rear to create a more "angular" look that echoed the brand's earlier 1970s styling.

The rear was modified with a more squared-off trunk and tail lights sourced from a Peugeot 505.

Mostly identical to the high-end S-Class interior, though it featured a custom steering wheel with the Monteverdi emblem. Optional luxury "extras" included a built-in television and a voice recorder.

Of the three produced, two are reportedly held in museum collections (including the Swiss Museum of Transport in Lucerne), while the third has occasionally appeared for sale on the private market.