How TiNoleggio grew insurance upsell from 2% to 5% with two-week design and data sprints

TiNoleggio is Italy's leading car rental comparison and booking platform, bringing together offers from 75+ rental partners on tinoleggio.it and tinorent.com.

The team had two levers to pull: moving more people from search results to checkout, and selling more insurance, the platform's main margin driver. With dozens of variables affecting conversion, they needed a reliable way to find out what actually moves the numbers.

Donux works as TiNoleggio's embedded product design team. Every year we run 12 Data Sprints, two-week cycles focused on one measurable objective, and 3 Design Sprints for larger structural work. Each sprint has the same rhythm: one week of co-design with TiNoleggio, one week of handoff to their developers.

Before the first test, we made sure the numbers could be trusted: an experimentation setup (GrowthBook first, now PostHog), a Looker Studio dashboard updated daily, and significance thresholds agreed with the team. From there, every idea became a test. Some won and shipped. Some didn't, and told us where not to spend more time.

The results page is where every point of click-through compounds across thousands of daily sessions. We tested how offers are presented and how users move to the booking step, and shipped the winners: a simpler step between results and offer brought +3.8% bookings, and click-through from the results page grew by 2 percentage points.

Fewer than half of users even noticed the insurance options. We designed a dedicated insurance step with positive, clear framing ("you're covered up to €6,000") instead of fear-based copy, designed to respect EU consumer rules.

The upsell rate went from around 2% to a 5% baseline, with peaks above 10% in high season.

Some wins don't show up in a conversion chart. Incomplete billing data was forcing manual fixes every day, so we redesigned the billing form and moved it before payment. Session recordings helped us iterate until the new flow had no measurable impact on conversion, while manual fixes dropped to almost zero.

Since the engagement started:

— Insurance upsell from ~2% to 5%, with peaks above 10% in high season

— Average insurance ticket from €15 to €17

— +3.8% bookings from a redesigned step between results and offer

— +2 points click-through from the results page

— Manual billing fixes from ~150 a month to almost zero

A shared UI kit keeps every new screen consistent, and the partnership continues sprint after sprint.