What Car Dealers Can Learn from Enthusiast Auctions Like ‘Bring a Trailer’
Part One of a Two-Part series. Published in Dealer Marketing Magazine April 30, 2025
By Ed Steenman. DMM Expert Panel
Car dealers across the country have been noticing a shift in how cars are being bought and sold. Traditional wholesale channels are still the backbone of the industry, but online enthusiast car auctions—like Bring a Trailer, Cars & Bids, and Pcar Market—are creating a new market dynamic. These auctions are not only for collectors, but also for dealers who want to track trends, better understand customer preferences, and make smarter decisions about inventory.
I sat down with John Polnik, the co-host of Bid Nerds, a twice weekly YouTube show that analyzes the results of cars sold on these enthusiast auction platforms, to discuss the implications for car dealerships. Bid Nerds provides insights into pricing trends, auction outcomes, and what makes a car a hit with bidders.
Here’s what he had to say about how dealers can use this information to their advantage.
Ed: Let’s get right into it: Why should a dealer care about platforms like Bring a Trailer?
JP: Simply put, they’re the best real-time valuation tool you’re not using. These platforms are public marketplaces where actual enthusiasts are bidding with their wallets every day. If you want to know what a specific Porsche 911, or M3 is really worth (not just what the book says) you look at recent Bring a Trailer results.
Dealers who pay attention to these auctions are already finding ways to make more money on trades, retail harder-to-sell cars to a national audience, and stay ahead of trends that traditional tools miss.
“Bring a Trailer and similar platforms are real-time market guides. Dealers ignoring them are leaving money on the table.” — John Polnik
Real-World Example: Avoiding Major Valuation Mistakes
Ed: Can you give an example where this knowledge could make or break a deal for a dealer?
JP: Definitely. Let’s say you’re working a trade on a 2014 Porsche 911. If it’s a PDK automatic, maybe $50,000 is fair. But if it’s a manual? Bring a Trailer sales show that could be a $75,000–85,000 car. Traditional valuation tools like KBB and NADA won’t capture that difference. In fact, they often deduct value for a manual transmission because it’s cheaper when new. If a dealer offers $50K for that car, the customer who’s done their homework will walk, or worse, feel insulted.
By watching auctions, you have live proof of the true market value.
Understanding the Platforms: Not Just Another eBay
Ed: Some readers might be thinking, “Okay, but isn’t this just another eBay Motors situation?”
JP: Not even close. Bring a Trailer, Cars & Bids, P-Car Market aren’t free-for-all marketplaces. They’re curated platforms. Not every car gets accepted. They focus on enthusiast vehicles: sports cars, vintage SUVs, rare or special editions. Cars are vetted. Listings are full of high-quality photos, real documentation, and ongoing community commentary. It’s a smarter, more serious environment: one that rewards quality and transparency.
Bid Nerds: Where Dealers Can Learn the Game
Ed: Tell us about Bid Nerds, how does it fit into all this?
JP: Bid Nerds is a live show that streams Sunday and Wednesday nights. My co-host Michael Deeb and I pick interesting cars from across the auction world, predict what they’ll sell for, track the final results, and break it all down. It’s a mix of education, entertainment, and community discussion. It’s incredibly valuable for dealers who want to sharpen their instincts about what’s happening in the enthusiast market right now.
[End of Part One]
Look for Part Two going live on 17 May, where John explains how dealers are successfully selling through online auctions and how to avoid common pitfalls that can ruin a listing.