How to set up an LED matrix display in your car window

What you'll need

• A PixelBoard LED matrix (Medium or Large fits most rear windows)
• A 5V USB-C cable (included) and a car USB outlet or 12V → USB adapter
• A microfibre cloth and isopropyl alcohol for clean suction adhesion
• The free PixelBoard app on iOS 14+ or Android 10+

Step 1 — Pick the right size

Measure the inside of your rear window. The Medium PixelBoard (32×16 pixels) suits sedans and hatchbacks; the Large (64×16) is better for SUVs and pickups where you want the message readable from further back. For side windows or dashboards, the Small panel works best.

Step 2 — Clean the glass and mount

Wipe the inside of the window with isopropyl alcohol and let it dry — this is the single biggest factor in suction-cup hold. Press each cup firmly into the glass for two seconds. PixelBoard sits flush against the window with the LEDs facing outward.

Step 3 — Connect USB power

PixelBoard runs on 5V over USB-C. Plug the included cable into any car USB port, a 12V cigarette-lighter USB adapter, or a USB power bank if you want to run it while parked. Average draw is under 5W on full brightness — well within any modern car outlet.

Step 4 — Pair the app and design your message

Open the PixelBoard app and tap Pair device. It connects over Bluetooth 5.3 in a few seconds. From there, type text, pick a font, drop in emojis, or use one of the built-in animations. Anything you design syncs to the display instantly.

A note on local laws

Rules around vehicle-mounted displays vary by country, state and even city. As a general rule: don't display anything that mimics emergency services, distracts other drivers, or obstructs your own view. Check local regulations before running animations while driving — many users keep PixelBoard static on the road and run animations only while parked.