Car Wi-Fi and car internet have become pretty much interchangeable terms, and while some modern cars come with this built in, ours didn't. We wanted a solid, reliable internet connection on the road for both work and pleasure — and we wanted to do it with as few compromises as possible.
Using a phone as a hotspot is the obvious option, but it's far from ideal: you need to dig into settings to let devices connect, it drains your phone battery, and both speed and coverage tend to be average at best.
With any radio installation — and especially in a car — there's always a trade-off between performance and practicality. The best coverage comes from antennas mounted as high and as externally as possible, like mobile phone masts. But the more you prioritise coverage, the less practical (and less attractive) the car becomes. Go the other way, prioritising looks and convenience, and coverage suffers — modern smartphones with no external antenna are a perfect example. We wanted to find our own balance: the best possible car Wi-Fi without making the car look like a lunar rover.
We built the system around a 4G router with the ability to connect external antennas. This matters because a car's metal body acts like a Faraday cage, making it hard for radio signals to get in or out — so getting an aerial to the right spot was key to performance.
Mounting an antenna outside on the roof would give the best signal, but it isn't practical without drilling through the bodywork and running long cable runs — and the longer the cable, the more signal is lost along the way.
Instead, we used the small patch of glass around the rear-view mirror. Unlike the rest of the windscreen, this area has no UV coating, and is actually designed to let radio signals pass through cleanly. We fitted a MIMO antenna here — a technology that uses two antennas working together to capture more signal and improve reception — and ran the cabling neatly through the interior trim panels to the glovebox, where the router itself was mounted.
For power, we tapped into a circuit that switches on with the ignition, charging the router's internal battery and allowing it to keep running while the car is parked. We also configured the router to power down automatically when nothing is connected, to preserve that battery further.
Choosing the right SIM took some trial and error. We started with a one-month preloaded data SIM, stepped up to three months, and once we had a good idea of our typical usage, settled on a 12-month SIM preloaded with 120GB — we're now on our second one of these.
The result is internet that's simply there whenever it's needed. The kids can use it on long drives, and we even get Wi-Fi calling on our phones as a backup when mobile signal gets patchy — which, as it turns out, is almost everywhere. Because the car's data SIM is on a different network to our phones, coverage black spots are reduced too, and stretches of road that used to guarantee a dropped call are now a thing of the past.
Get in touch
