Artcurial

It requires at least $10 million to buy a Ferrari 250 GT California Spider at auction. Two California Spiders (one SWB, one LWB) will be auctioned during Monterey Car Week this year, and how they fare will be a key indicator for the top end of the market.

Car auctions have made the digital transition far better than most industries, and while we may no longer have the rampant bull market of a few years ago, the collectible car industry looks in better shape than ever. Here's a selection of the more interesting lots that sold in Paris.

Three-time Formula One Champion Ayrton Senna continued to smash records 25 years after his death at Retromobile last weekend, setting new auction price records for a Formula One helmet ($184,340 | €162,000​) and race suit ($110,372 | €97,500​).

Ducati, Honda, Munch and MV Agusta have all broken auction marque records repeatedly in the last few years as 1970s motorcycles have come into vogue. A collection of MV Agusta motorcycles to be auctioned in Paris later this week will almost certainly raise the bar higher again ... maybe much higher.

The Ferrari 250 GTO is the "Holy Grail" for car collectors. All 39 made still exist, and owning one of these exquisite V12 road-registerable racing cars is the ultimate badge of success. With recent unconfirmed private sales of $52M and $70 M, the stage is set for a showdown in Monterey.

One of the most significant cars in history will sell at Monterey this week, and it isn't the Ferrari 250 GTO.​ This Ferrari 275P won the 24 Hours of Le Mans twice, was the first mid-engined car to win, and twice set record distances for the event.

The Volkswagen Beetle continues to defy the laws of economics, becoming one of the hottest collector car investments at the same time as being the most plentiful. Though the collector car market has cooled, 36 of the 50 most valuable Beetles have been sold in the last three years.

Rétromobile has been running since 1976, when the most expensive car in the world cost less than $100,000 and long before the term retro had become fashionable. It is one of those places where auctions truly can throw up some remarkable objets d'automotive art. This year it did not disappoint.

The Bugatti marque was once the most revered of them all. Twice it has been resurrected, but several spectacular showings this week at Retromobile indicate the Bugatti name is returning to its glorious former levels.

There have been many fabulous children's cars we have chronicled over the last few years, ​ but this 1927 4.5-liter Bentley scale replica children's car heads for sale during Retromobile in Paris this week, and it is estimated at just €5,000 to €7,000.​

This 2003 Bentley Arnage-based estate car is perhaps the most lavishly crafted station wagon in history. It began life in 2003 as a brand new 500-hp, twin-turbo 6.75-liter Bentley Arnage, and was purchased by an Italian industrial heir with some exclusive modifications in mind.

In our ongoing efforts to offer more useful auction reports, we've configured the most valuable, the biggest "no sales" and the more interesting offerings at this month's Retromobile auctions in Paris.