Halo: Vehicle Experience Concept
One driving experience across an AR head-up display, instrument cluster, center screen, CarPlay and CarPlay Ultra
At a glance
I acted as design lead and executive sponsor. I set the vision, ran the research, wrote the principles and decision records, and used Claude (AI) to help build working prototypes of every screen and as my prototyping partner.
The challenge
Premium cars put information on the windshield, behind the wheel, in the center stack and on a projected phone UI, each built by a different team. Only the driver sees all of them at once, at highway speed. The goal: one system that keeps eyes on the road.
What I led
- Set the north star: four screens designed as one system, measured by eyes-on-road time
- Ran secondary research on BMW, Audi, Cadillac and CarPlay Ultra, plus driver complaints about iOS 26 CarPlay
- Defined three proto-personas and a primary research plan to validate them
- Designed a three-plane HUD: AR world, driver plane and a panoramic band
- Shrank the HUD to two-thirds of the display to give speed and tach a classic home
- Designed the center screen with a theme that follows the sky and HUD settings with a live preview
- Explored two CarPlay directions and a CarPlay Ultra cluster and center screen
- Wrote six design decision records tied to NHTSA’s 2-second and 12-second glance guidelines
- Built working prototypes of every screen, sharing one live state
The outcome
A complete cockpit concept with working prototypes, decision records and a research plan, ready to take into a simulator glance study and a knob usability test.
Overview
Halo is a vehicle experience concept for a premium car brand. It treats the augmented-reality head-up display, the instrument cluster, the center screen, and the phone as one system, with one type family, one color language, and one motion language. Each screen has a single job, and no setting or phone app can hide something safety-critical.
How I led it: I acted as design lead and executive sponsor. I set the vision, ran the research, wrote the principles and decision records, and used Claude (AI) to help build working prototypes of every screen and as my prototyping partner.
What’s in the concept:
AR head-up display: three depth planes, sized to two-thirds of the display so a classic speedometer and tachometer sit below
Center screen: a light and dark theme that follows the sky, drive modes, climate, and full HUD settings with a live preview
CarPlay: two concepts that fix knob focus, voice, and interruption problems
CarPlay Ultra: a themed phone-drawn cluster and a center screen that blends phone and car controls
Safety: speed and collision alerts stay on, and alerts clear the HUD to a single message
Services
UX Strategy, Customer Research, Interaction & Visual Design, Design Decision Records, Interactive Prototyping
Client name
Halo (self-initiated concept for a premium marque)
Team
John Karl, Design Lead & Executive Sponsor
Prototype
Market research
User research
UX Decision
This is a working prototype. Follow the guided steps or switch tabs and use the controls. Everything responds live.
Market research
Goal:
Learn where today’s best systems succeed and where drivers struggle, before designing anything.
BMW Panoramic Vision: a pillar-to-pillar band any occupant can see, plus a 3D HUD for navigation. Gap: two layers need a clear rule for what goes where
Audi AR HUD: speed, signs, guidance and assist status on the windshield, named Motor Trend’s best tech of 2026. Lesson: it works because it stays sparse
Cadillac dual-plane AR HUD: near and far image planes. Halo extends this to three planes
CarPlay Ultra: drives the cluster and car controls with matching themes, but reviewers note heavy reliance on the phone and a mixed cluster experience
User research
Goal:
Ground every decision in real input from the people who use it, and say plainly what still needs validating.
Voice of the customer: iOS 26 drivers report grey focus on the selected button, focus landing on Back instead of Start, and voice routes that now wait for an on-screen choice
Proto-personas (hypotheses): the daily commuter, the enthusiast and the shared-car household
Research plan: drive-along interviews, a simulator glance study against NHTSA criteria, a knob usability test and a two-week diary study
Why Each UX Decision Was Made
Goal:
Every task should fit NHTSA’s distraction guidelines: no glance away longer than 2 seconds, and no more than 12 seconds in total.
Information at the depth it belongs: AR world, driver plane and band, so drivers read the next turn without refocusing
Speed in two fixed places: on the HUD and on a classic speedometer, so the glance target is always predictable
Personalize everything except safety: ten HUD items and three presets, with speed and collision alerts locked on
The interface follows the sky: Auto switches to dark at sunset to protect night vision, with Light and Dark as overrides
Focus is the brightest thing on screen: Go is selected by default, and voice routes start after a countdown that any input pauses
Alerts take the whole stage, briefly: one message, a lock on the hazard and red reserved for act-now moments
CarPlay and CarPlay Ultra
Goal:
Many drivers live in their phone. Design for both kinds of projection without losing the brand.
Example 1, CarPlay: Context Stack rearranges for driving, arriving and parked, and calls never cover the next turn. Focus-first makes knob and voice control dependable
Example 2, CarPlay Ultra: the phone draws themed gauges with live car data and directions between the dials. The center screen keeps car controls built in, with PHONE and CAR tags so drivers know what works without the phone
Final observations
A cockpit is a program, not a screen. Halo shows how I lead one: set a clear north star, settle debates with principles and decision records, and prove ideas with prototypes people can actually drive. Taking it to production, I would organize designers by surface into pods for HUD and cluster and for center and projection, with a shared design system. I would bring safety and engineering into a weekly decision review from day one. Next steps are the simulator glance study and a knob usability test, then a drivable prototype of the winning CarPlay direction.
John Karl
19 Years • Product & UX Design Leader Leading Mobile Product for 500K+ Users
If you like what you see or have any questions, feel free to send me an email anytime.
Selected work
[2010 -2025]
