Case Study
Improving Filter Discoverability for Car Buyers
Company
Autotrader
Role
UX Designer
Type
B2C, Web & Native iOS / Android
Year
2019
The Brief
65 % of users landing on Autotrader’s search results page weren’t engaging with filters at all — and 45 % were bouncing. Filters existed, but people weren’t using them.
Prioritizing the Right Problem
Our squad used bullseye diagramming as a recurring exercise to keep strategy current — separating immediate priorities from longer-term bets. Filter engagement surfaced as one of the highest-impact, most addressable problems on the board. That’s what pointed us here.
What the Data Told Us
With filter engagement confirmed as the priority, we dug into the numbers. Make, Model, and Body Style were the most commonly used filters — and users who selected both a Make and Model were most likely to convert. The filters that drove results were buried among ones that didn’t. The problem wasn’t the filters. It was how we were presenting them.
What Users Told Us
User testing confirmed what the data suggested. Users felt overwhelmed the moment they landed on the results page. Too many options, too little guidance — users didn’t know where to start, so most didn’t.
I’m not sure which filters to use..
What’s a ‘drive type’?
Two Directions
Armed with a clear problem, I moved into lo-fi concepts. The question was how to surface the most relevant filters without overwhelming users on arrival. I built a decision matrix to help the squad work through a genuinely difficult decision — each criterion carried different weight, and the matrix made that visible. Two directions emerged. We tested both to find out which helped users move faster.
Final Design
The solution was a contextual suggested filters layer — a recommendation service at the top of the results page based on how the user had arrived at the page. Rather than presenting every filter at once, the design guided users toward Make and Model first, the two filters most correlated with finding a car. Usability testing showed 80 % of users engaged with suggested filters first, and 75 % continued into the sidebar without confusion.
Built to Last
Shipping at this scale meant staying involved past the design file. I established guiding principles for the engineering team, helped fill gaps as they emerged, and treated the handoff as a delivery — staying close to the implementation until the feature was live and behaving as intended.