A general view at Pebble Beach Concours d’Elegance on August 18, 2024 in Monterey, California. Since 1950, the annual Pebble Beach Concours d’Elegance has hosted the world’s most beautiful and expensive collectable cars on the Competition Field along Carmel Bay.Matt Jelonek | Getty Images News | Getty ImagesA version of this article appeared in CNBC’s Inside Wealth newsletter with Robert Frank, a weekly guide to the high-net-worth investor and consumer. Sign up to receive future editions, straight to your inbox.Up to $400 million worth of classic cars will roll across the auction block in Monterey and Pebble Beach this week, marking the biggest test of the year for the collectible car market and wealthy owners.An estimated 1,140 classic cars will come up for sale at Monterey Car Week, the annual gathering of classic car collectors from around the world. The sales total is estimated to come in between $367 million and $409 million, according to Hagerty. The midpoint of that range, at $388 million, would mark the third year of declines in sales, and an 18% drop from the recent peak of $471 million in 2022.The high end of the market is the weakest. The Monterey auctions – held by RM Sotheby’s, Gooding & Co., Mecum, Bonhams and others – have traditionally featured at least a half-dozen cars priced at $10 million or more. This year there’s only one – the fewest in over a decade. The average sale price has dropped to $473,000 this year from $477,000 last year.[embedded content]”Pebble Beach is the annual health check on the market,” said Simon Kidston, a classic car advisor and dealer. “Everybody waits to see what happens at Pebble Beach before committing to a major decision the rest of the year.”Like the art market and other types of collectibles, classic cars have been in slow d …