This summer, millions of dollars’ worth of cars will find their way to new homes via the world’s most prestigious auctions, in Pebble Beach, Calif.

Sales predictions this year are cautiously optimistic. Usually election years spark a lull in pricing because potential buyers are uncertain about the future, but great cars will always earn multimillion-dollar price tags, said Ian Kelleher, the car specialist for RM Sotheby’s.

So far this year, the major vintage car auctions have seen bigger dollar figures than in 2015. But the overall sell-through rate this year is down to 65 percent compared with 87 percent last year—in other words, fewer of the cars on offer have ended up getting sold.

So if you have an important vintage car you want to unload in 2016, what should you do?

Where to Begin

First of all, start early. The longer an auction house has to photograph, film, and otherwise market your car, the better. And if you want to sell your car through one of the world’s top auto auction houses (Gooding & Co., RM Sotheby’s, Bonhams, Russo & Steele), you should start now. Most are taking considerations for consignment for the Monterey auctions until the end of June.

“We are going to spend a lot of money marketing the car,” Kelleher said, noting that the Monterey auction costs the company more than $1 million to produce. Printing auction catalogues and promotional materials alone can cost more than $100,000. “Ultimately it’s about value-added services, so the longer we have to work with a car, the more we can do.”

But before you jump into a sale, consider a few things first. Does your car have the provenance and racing success that might make it appealing? High-end auction houses work hard to ensure that their sales—especially the most prestigious at Pebble Beach—have a lot of variety in the portfolio. Often they’ll take only one of a certain model.

“We try to consign a wide variety of cars—everything from $100,000 cars to $10 million cars and above,” said David Gooding, president of Gooding & Co. “We want different eras, all different types and marks. We try to [choose] the best we can find but also cars that are priced sensibly—because it’s not a car show, it’s an auction.”

Know Your Angles