As the video below shows, it looks like all you need to do is connect your iPhone (Android support arrives sometimes later this year) to your Jag's infotainment system via USB. From there, everything is handled via the car's touchscreen. How this differs from other mobile payment tech, Jaguar says, is that this one uses geolocation in concert with PayPal or Apple Pay for transactions.
The functionality launches February 15th in the UK and additional availability will roll out over the course of this year. Jaguar says that additional applications of the tech could include drive-through restaurants and parking services. Which, to be honest, sound far more convenient than paying for gas. I mean, you still have to get out of your car for the former. The latter? It should eliminate the awkwardness of digging your wallet from a back pocket while you're seated.