With ever-more-strict legislation worldwide defining the possible shapes and forms of modern automobiles, not to mention the ever-present laws of aerodynamics, there is little wonder why all modern cars tend to look the same. Viewing a sea of late-model crossovers will make anyone yearn for the past, a time when handbuilt quality and attention to detail were valued in the extreme. This year, the world's premier auction company for premium motorcars returns to the Portola Hotel and Spa in Monterey, bringing with a record offering.

As the total number of automobiles and automobilia adds up this year to more than 190 lots, including four distinctive collections, the team at RM Sotheby's decided to compile a "Spotter's Guide" to help filter through all the exceptional offerings. Also useful as a scavenger's hunt, after appreciating the details of these unrepeatable offerings, you may want to take one home:

1964 ferrari 250gt

1964 Ferrari 250 GT/L Berlinetta Lusso by Scaglietti | Estimate: $1,750,000 – $2,250,000 USD

We begin with a Ferrari that is widely regarded as one of the most beautiful grand touring cars ever made. Typically described as elegant and perfectly proportioned, the key to the 250 GT/L Berlinetta's design is that no one detail overwhelms the viewer. Ever after known as simply "Lusso" (Italian for "luxury") for its balance of sporting abilities and comfortable ride, this prancing horse has inspired the look of many subsequent Ferrari models. The detail that made it so exceptional in-period—even more than its chromed "egg crate" grille—are these subtle bumperettes, which integrate the front turn signals. The envy of many sixties (and seventies) sports cars.

1935 mercedes benz500

1935 Mercedes-Benz 500 K Cabriolet by Saoutchik | Estimate: $1,750,000 – $2,250,000 USD

Offered from Masterworks of Design

Befitting their status as hand-made classics, a great number of the cars on our list have had their bodies custom-built by coachbuilding houses. A tradition that extends to this day, coachbuilding houses offered their clients essentially free reign in terms of interior and exterior appointments. While some coachbuilders were known for their conservative approaches, the French firm started by Jacques Saoutchik produced wonderfully over-the-top designs that were wholly original and shaped as much by the wind as the wishes of their clients. A side-mounted spare tire cover is the detail to notice on this example, one of only two Saoutchik designs completed on a Mercedes-Benz 500 K chassis.

1939 mercedes benz 540k

1939 Mercedes-Benz 540 K Special Cabriolet A by Sindelfingen | Estimate: $1,750,000 – $2,500,000 USD

Offered from Masterworks of Design