Bought engineering 6 months of runway with a research-led redesign — and lifted mileage reporting 13%.
2022
SIXT+ subscribers had to report their mileage every month, but 45% didn't — creating penalty disputes and unreliable data. Engineering needed time to build automated reporting. Rather than wait, I ran the research and designed a bridge solution that fixed the customer experience now and bought the business the runway it needed. The work was strong enough that SIXT then overhauled its entire customer messaging system around it.
WHAT I PERSONALLY OWNED
This was research and product strategy first, design second:
The strategic problem
This wasn't briefed as a design task — it was a business risk. Automated mileage reporting was months away, but the manual flow was failing now: 45% of users never reported monthly
30% were hit with penalties at branches (higher in the US).
26% who raised their mileage plan dropped it again the next month — churn-like behaviour that signalled confusion, not need.
The question I had to answer wasn't "how do we make this prettier," it was "how do we hold the entire ecosystem together while engineering catches up?"
FRAMING THE RIGHT PROBLEM BEFORE RESEARCHING
Before talking to a single user, I mapped the existing mileage-entry and mileage-plan journeys as task flows. This told me where the friction could plausibly live and shaped what I actually needed to learn — so the research was targeted, not exploratory for its own sake.
UX analysis conducted for current mileage entry & mileage plan flow
THE RESEARCH
I, along with researcher ran primary research (interviews and a task-based study against a defined research plan) and secondary research (a heuristic evaluation across the subscription lifecycle, plus analysis of support interactions to test my hypothesis). The friction clustered into three areas:
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Awareness (users didn't know the benefits, or that penalties were coming), Usability (the "Enter Mileage" action was hard to find), and
Clarity (dense text, confusing emails blending rental and subscription language).
THE INSIGHT THAT SHAPED THE SOLUTION
German users place high value on rules, privacy, and safety. Both primary and secondary research confirmed the existing journey lacked the clear instructions and transparent protocols they expect — so the fix wasn't decoration, it was meeting a cultural expectation of clarity and trust.
Primary & Secondary research findings
From Insight to Strategy
I aligned three sets of needs — users, stakeholders, and market — into a single set of product goals, then prioritised ruthlessly because the timeline was tight.​
Product Goal
IDEATION
I classified the issues into distinct categories encompassing communication, content, reporting mileage, mileage plans, and the mileage details screen. Then brainstormed potential solutions for each issue, organized them into distinct categories to eliminate redundancy, and structured them to determine the final solution. Evaluation was based on technical feasibility and what best served the combined needs of users and the business.
Solution ideation through brainwriting
HOW DID I DECIDE WHAT TO BUILD FIRST?
I used a severity framework scoring each issue on three axes:
Frequency (how often it bites),
Impact (how hard it is to recover from), and
Persistence (one-time confusion vs repeated friction).
High-frequency, high-persistence issues — the reporting nudges and the dense information — won priority over cosmetic fixes.
Analysing Different features prioritization
The Solution
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Well-timed nudges: Notifications, in-app messages, emails, and calendar reminders prompting users to report 10 days before renewal, plus missed-report alerts as a safety net — directly targeting the 45% who never reported.
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Clarity over density: I reorganised dense walls of numbers and text into scannable categories, so users could grasp what mattered and what to do — answering the German-user expectation of transparent, rule-clear communication.
User main journey flow (wireframe)
Effective nudges and reminders
App notification for mileage report
In app notification for mileage report
1st Email Reminder to report mileage
Simple & More organized
Mileage report - prototype
Outcome
Observed a 13% rise in mileage reporting within 60 days.
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Data is now more organized, clearly labelled and easy to find.
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The problem solving journey & design impact proved that little nudges make a big business difference, leading SIXT to overhaul all their customer messaging.
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Enhanced cleanliness and aesthetics of presentation.
New Designs
Existing Designs
What made this work?
The win came from treating this as a research and prioritisation problem, not a redesign. Mapping tasks before researching kept the study focused; the severity framework made sure limited time went to the issues that actually drove the 45% non-reporting; and grounding the solution in the German-user insight meant the nudges read as helpful, not naggy. The proof of impact: a "small" messaging intervention lifted reporting 13% in 60 days and convinced SIXT to overhaul customer messaging company-wide. Next time I'd run a quick A/B on nudge timing and tone before full rollout — measuring the channel mix is now how I de-risk any communication-led solution.