a new lexus hmi system that enhances both digital and driving experiences.‍‍

drawing on lexus’ heritage and premium values, this interface offers intuitive controls, refined aesthetics, and advanced features for a truly elevated user experience.

overview‍‍

to enhance our understanding of the current lexus Hmi system, the process began with a holistic mapping of all aspects that the lexus rz300e/450e could offer, focusing on interface design to shape the overarching concept of a premium, comfortable, and euphoria-driven experience.

Lexus' current interface‍‍

the current lexus interface system inherits from toyota’s interface, showing no fundamental differences in terms of visual and functional design. while it remains traditional and reliable, it lacks differentiation. in addition, the design language appears outdated, and the overall positioning is unclear.

Lexus' positioning‍‍

to better understand the design of the rz300e/450e and identify potential issues, a review of the competitive landscape from a macro perspective helps clarify its positioning. In this section, a selection of representative suvs currently on the market are compared across two dimensions: personality vs. reliability vs. economy vs. premium.

• reliability refers to the degree of the holistic driving experience - from pre-driving to post-driving - encompassing stability and safety in both the vehicle and after-sales service.
• premium refers to the level of design and quality in both hardware and software, characterized by deliberate and selective choices that reflect the brand’s value.

field research & interview‍‍

to enhance the design process, I conducted field research focusing on three key areas:

• current hmi trends - analyzed emerging trends in human-machine interfaces, emphasizing usability and evolving market standards.
• design observations - documented practical insights from existing automotive hmi systems, identifying strengths and areas for improvement.
• market research results - compiled feedback from direct interactions with stakeholders to align design directions with user expectations.documented practical insights from existing automotive hmi systems, identifying strengths and areas for improvement.

I visited  lexus dealerships and engaged in face-to-face conversations with three key stakeholder groups. The following insights were gathered.

the current hmi system fails to effectively convey lexus’ core brand identity - the premium, comfortable, and euphoria-driven experience.

ava is a 28-year-old businessman, who owns a lexus rz300e. she needs this premium car to fit her business and vibrant ambient for daily commutes and short trips. she expects a well-designed interaction system that matches his trendy lifestyle.

user persona‍‍

to better understand lexus rz300e/450e users, a persona was created representing someone who values quality and life's finer details. this user seeks a refined, seamless driving experience that emphasizes safety, comfort, and personalization.

affinity diagram‍‍

reimagined the hmi system started by analyzing all features of the lexus rz300e/450e and exploring their integration. the new system focuses on three core attributes – premium, comfort, and euphoria.

card sorting

next, grouped similar features and functions based on the affinity diagram to refine and streamline the hmi system.

end-to-end user journey‍‍

the user journey analysis focuses on short trips with friends which combine multiple attributes - family, travel, entertainment, and commuting - providing a richer, detailed understanding of lexus' current driving experience and brand messaging. based on this comprehensive view of the experience, opportunities for improvement can be further identified.

core scenarios‍‍

Based on the journey map, we identified key features that directly impact the driving experience. Using MoSCoW prioritization, the Lexus redesign will focus on necessary and important sub-features - ranging from menu navigation and route selection to in-drive monitoring and personalized audio control.

Restructuring the Lexus Interface

The revised IA streamlines the interface by removing redundancy and adding key functions like navigation flow, sound customization, and real-time vehicle monitoring for a clearer, more premium experience.

wireframes‍‍

prototype‍‍

2. Navigation system for every driving moment

The redesigned map feature supports the full navigation journey—from planning to post-arrival.

• faster route setup with simplified flows.
• during driving, the system maximizes real-time display of vehicle data for safe and informed decisions.
• after arrival, the system presents trip stats and energy feedback to complete the euphoric drive experience.

3. Personalized Audio & Immersive Entertainment

Customizable audio settings offer a refined, in-cabin sound experience aligned with Lexus’s holistic identity.

• personalized sound configuration through curated modes along with elegant motion graphics.
• high-freedom tone controls let users fine-tune acoustic details, enhancing control and sensorial depth in every moment.