Known limits

What still needs work

We list these so that if you run into one, you know it is a known issue we are tracking — not a fault with your device.

Data for Vietnam only

This is a deliberate scope: offline maps, routing, the place directory, speed limits, lights and signs are all built for Vietnam, with no plan to expand. Outside Vietnam the status line says “Outside Vietnam”: the base map still shows, but there is no search, navigation or speed limit. If you are abroad and want to see how the app works, turn on “Try it in Vietnam” in Settings — a simulated car drives in District 1, Ho Chi Minh City.

The free version needs data for signs, cameras and lights

Signs, enforcement cameras, traffic lights and speed limits are downloaded in small pieces around the car, ahead of it and along the chosen route, and kept on the device for about 24 hours so they still work in tunnels and dead zones. After a long time without signal on a road you have not driven, the app may not have signs or cameras for it. A purchased Pro plan adds nationwide data stored on the device that works with no connection at all; the 30-day trial does not include this offline data. The 145 MB offline map is free for everyone.

Road-segment speed limits do not always match the sign

Where the data has no sign for a road, the app uses the default for the road type and your vehicle type. Only real signs are read aloud as you pass them; road-type numbers appear on the sign silently. Right after opening the app while parked, the sign may show “-” until the app knows which road you are on.

Stacked interchanges

Where a flyover sits right above a service road, the app may think you are on the road below, because the two have nearly the same position and direction. The app prefers the bridge at speed, tells road levels apart and looks at the recent sequence of positions rather than single points, but this remains a weak spot. If it happens, the quickest fix is to correct the limit from the car.

Road recognition while the map is dragged or covered

The app mainly recognises your road from the part of the map being drawn on screen. When you drag the map away, or the screen shows the reverse camera or another app, it switches to offline road data — the road name and class can be less accurate meanwhile, while the speed sign keeps updating from your position. The map returns to the car after 12 seconds on car screens, CarPlay and Android Auto, and after 5 seconds on phones.

Offline directions on Android have no street names

Without signal, the Android version computes the route on the device and can say “turn right” but not yet “turn right onto Le Loi”. With signal, directions include street names. The iPhone version uses its own offline routing data and keeps street names offline.

Routes do not yet account for time-based bans or vehicle size

For trucks the app uses truck routing, so restrictions already in the map data are respected, but it does not know your vehicle’s height or weight, nor time-of-day bans. Cars avoid small alleys; ferries are avoided by default; you can choose to avoid tolls and motorways. When following a suggested route, please keep an eye on the road signs — the final choice of road is always yours.

Forward-vehicle warning needs a camera with a clear view (Pro)

The camera must face the road, its lens height must be entered correctly, and the head unit must let apps read the camera — AHD cameras plugged into the video input are usually wired straight to the board, so Android cannot see them. Measured distances are off by roughly 20–30%, worse at night, in heavy rain or with a dirty windscreen. On iPhone only the phone’s own camera can be used. This is a reminder, not an automatic braking system.

Traffic lights: the app does not know the current colour

The app knows where lights are but not their cycles — there is no data source for this in Vietnam yet. It announces “traffic light ahead” the way it would a sign. Newly installed lights may be missing.

No no-stopping / no-parking sign data yet

The app can remind you when you stop where parking is banned (including odd/even-day signs), but the current data does not include these signs, so you will not hear the reminder yet. We will add them once the data is reliable.

The community map depends on how many people contribute

A sign is published only after three different devices report it, so on quiet roads it takes longer. Incidents appear from the first report but are only one person’s word, and expire unless someone confirms them: jams and accidents after 15 minutes, police after 30, closures, landslides and floods after 60. Community speed signs show on the map but do not change the number on the speed-limit sign.

OBD-II reads the standard parameters only (Pro)

The app reads RPM, speed, coolant and oil temperature, fuel level (%), voltage, engine load and fault codes. Tyre pressure, fuel in litres and air conditioning use undisclosed, maker-specific addresses, so they cannot be read; doors, lights and turn signals need a profile per model, which we do not have yet. For tyre pressure you can use the Bluetooth TPMS sensors or USB receiver the app supports. On Android, Bluetooth LE adapters “for iPhone” do not work — use a regular Bluetooth (SPP) or WiFi adapter; on iPhone it is the other way round, Bluetooth LE or WiFi only.

The Mika assistant needs a connection and its own plan

Mika understands you through our server, so it cannot answer without signal (that turn is not charged). Mika has its own plan, separate from Pro; the 30-day trial includes some Mika usage.

The dashcam stops recording when storage is nearly full

Video is recorded in a loop, deleting old clips within the space you choose. The app warns at 80% of device storage and stops recording at 95% so the device does not freeze. Clips you have locked are never deleted automatically, so remember to clear them out.

Android Auto has a few restrictions of its own

Under Google’s rules for car screens: dashcam video cannot be played back on the car screen, typing works only when parked, and Mika uses the car’s microphone.

Very short trips are not saved

Trips under 300 m do not go into your history. This is deliberate: backing out of a parking spot or creeping a few metres also counts as a trip, and a list full of those is hard to read.

Limits you correct are stored on this device only

Your corrections are stored on the device and always take priority over every other source. If you change head unit or uninstall the app they may be lost, as there is no sync between devices yet. To share a correction with everyone, report it on the community map.

Pro does not move between apps automatically

A plan bought in the phone version (Google Play) does not automatically apply to the iPhone version or MapCar Launcher, and vice versa. When you buy on a phone or iPhone, the app gives you an activation code to unlock a car screen — one code per device. Car screens without Google Play cannot buy in the app and use this code instead. MapCar Launcher is a separate product, bought by bank-transfer QR inside the Launcher.

Older head units need a separate build

Some older head units only support OpenGL ES 2.0 graphics (MT8227L, Allwinner T3, Rockchip PX3…). If the map does not show after installing, please download the build for older graphics from the Download page.

Up to date with the app as of 16 October 2026.