About Bring a Trailer

Bring a Trailer

Bring a Trailer — known to enthusiasts as BaT — is an online auction platform and publication for classic, collector, and enthusiast vehicles, based in San Francisco, California. Founded in 2007 by Randy Nonnenberg and Gentry Underwood, the site began as a simple blog sharing links to interesting cars for sale and evolved into the world's largest enthusiast and collector car auction platform, selling $1.37 billion in vehicles in a single recent year and surpassing 100,000 total auctions. Acquired by Hearst Autos in 2020 while continuing to operate independently under Nonnenberg's leadership, Bring a Trailer has transformed how collector cars are bought and sold — replacing the opaque, high-fee world of physical auctions with a transparent, community-driven online marketplace where comments, scrutiny, and shared knowledge set the terms.

Founding: From Email Chains to Car Blog

Bring a Trailer was founded in 2007 by Randy Nonnenberg and Gentry Underwood, two friends who were exchanging far too many emails about cool cars for sale on Craigslist and eBay. Nonnenberg — a Northern California native with a background in technology and mechanical engineering, who had worked at Adobe, Macromedia, and Yahoo, and spent ten years in engineering and production at Audi and BMW (including time in Germany) — started the site with a college buddy as an easier way to share car links than emailing them back and forth. "Whether I was in the market for a car or not, I was always looking at cars on eBay and Craigslist, and I'd help friends find cars, too, sending them links and stuff," Nonnenberg recalled. "So the start of it was a very basic blog format. It was a very immature experiment to just start writing about cars." The experiment found an audience: more people wanted help finding cool cars than Nonnenberg had expected, and the blog's following of enthusiasts grew steadily. Nonnenberg made Bring a Trailer his full-time career starting in 2010.

The Auction Model: Curation and Community

In 2014, Bring a Trailer launched its online auction platform — and the collector car world was changed forever. The model rests on two pillars: curation and community. BaT's team curates the vehicles submitted for auction, selecting distinctive classic, collector, and enthusiast cars (and later motorcycles, parts, and more) and presenting them with diligent, honest listings — extensive photography, documentation, and forthright descriptions of condition. Then the community takes over: the comment stream stays open throughout each listing's preview period and the auction itself, allowing knowledgeable enthusiasts to discuss, scrutinize, and debate every detail. This transparency reduces surprises and lets buyers bid with confidence. As the company explains it, the goal is to help match buyers with the right car, not to talk up cars to set price records — a philosophy that distinguishes BaT from traditional auction houses.

How BaT Differs From Physical Auctions

Bring a Trailer's founders positioned the platform explicitly against the traditional collector-car auction model. Where physical auction houses can charge as much as 20 percent in combined seller commissions and buyer premiums, BaT's fee model is 5 percent of the sale price with a cap of $5,000 — dramatically more affordable. Where traditional auctions rely on the auctioneer's patter, BaT relies on community scrutiny: serious bidders only (bidding requires a credit card and deposit), extended end times to eliminate sniping, and open comments that surface flaws as readily as virtues. Bidders participate from anywhere via computer or smartphone, rather than traveling to Monterey or Scottsdale. The result, in the words of longtime users, is "how auctions should work" — a paradigm shift that forced even established classifieds like Hemmings to launch competing online auction products.

Growth: From 450 Cars to a Billion-Dollar Marketplace

Bring a Trailer's growth has been extraordinary. In its first year of offering cars to the public, 2014, BaT listed 450 cars at an average sale price of $21,000 with a 72 percent sale rate. By 2019, it was listing 7,718 auctions per year at an average of $28,000 with a 74 percent sale rate; more than 200,000 people received its daily email of closing auctions, and more than 15,000 people had won at least one auction. In a recent year, the site sold $1.37 billion in vehicles, making it the largest enthusiast and collector car auction platform in the world. In 2025, BaT hit its 100,000th auction — marked by selling its company-owned 1973 Datsun 240Z with proceeds donated to The Piston Foundation, which supports careers in the collector car industry. Big-money buyers, including celebrities like Michael Strahan (who bought a rare 1994 Porsche 928 GTS manual coupe on the platform), have validated BaT's arrival at the top of the market.

The Hearst Autos Acquisition

In June 2020, Hearst Autos acquired Bring a Trailer for an undisclosed price. Hearst Magazines president Troy Young framed the deal as "another step in the evolution of Hearst Magazines, one that connects passion points to content and now, marketplaces": "At its core, Bring a Trailer is about curation, which is what our brands have always been about." The platform continued to operate as an independent business led by Nonnenberg and his team from its San Francisco headquarters, with Hearst Autos — publisher of Car and Driver, Road & Track, and Autoweek — providing investment in technology, new products and features, editorial content, and sponsorship opportunities. "I had Road & Track magazine pages hung on my walls as a kid and they helped shape my automotive passion," Nonnenberg said. "This is really an amazing next step in the Bring a Trailer journey." Nonnenberg remained involved as a board member and advisor, continuing to lead the company he founded.

Community, Content, and Culture

Beyond auctions, Bring a Trailer has become a community and content hub for car enthusiasts: a blog, forums, events, and the daily ritual of browsing listings that devotees describe as addictive — "like having your own personal assistant who scouts out all the cool cars, trucks, and motorcycles for sale." The comment sections function as rolling seminars in automotive knowledge, where experts weigh in on originality, provenance, and value. The site's daily email, listing auctions closing that day, reaches hundreds of thousands of subscribers. BaT has also expanded into adjacent categories, including a dedicated motorcycle marketplace. For many enthusiasts, the site is a daily habit as much as a marketplace — entertainment, education, and commerce fused into a single experience.

Impact on the Collector Car Market

Bring a Trailer's impact on the collector car market has been transformative. By making auction results public and searchable, BaT created unprecedented price transparency in a market long characterized by opacity. Its curated, community-vetted listings established new benchmarks for how collector cars are presented and evaluated. The platform's success demonstrated that online auctions could handle not just commodity used cars but six- and seven-figure collectibles — expanding the buyer pool globally and giving sellers access to the world's most knowledgeable audience. Traditional auction houses have had to adapt to the expectations BaT set: transparency, reasonable fees, and digital-first participation. Few internet marketplaces have so thoroughly remade their industry's norms.

Bring a Trailer Today

Today, Bring a Trailer continues to operate from San Francisco as the premier online auction marketplace for collectible vehicles, parts, and more — part of Hearst Autos, led by its co-founder, and still guided by the curation-and-community philosophy of its 2007 blog origins. With more than 415,000 users and 175,000 registered bidders vetting each vehicle at the time of acquisition — and far greater scale since — the platform remains the enthusiast market's central gathering place. From email chains between two friends to a billion-dollar marketplace, Bring a Trailer's story is a classic internet success narrative: find something people love, serve them honestly, and let the community do the rest. Its official website is https://bringatrailer.com.