Hi there, I own an E2-F6 and I have to say the app is one of the best I have ever used, really, it put's Arri, Red and Sonys equivalents to shame. Having said that it relies on wifi (like most of them) and disconnect. If the 'support' car will always be within a hundred meters and often behind then I would run the HDMI from the camera to a wireless transmitter (such as the Teradek) in the boot area.They have a pretty good 'line of sight range. If you send the camera display overlays over HDMI too then at the very least you can always see what's going on with the camera: exposure, battery voltage, media remaining, audio levels (you'll be able to hear it too, with a suitable monitor), framing etc.
Then you can use the app to control the camera as and when you're connected/close enough. And you can do SO much from their app. Definitely look into the eND module too, it allows you to ride the exposure almost seamlessly from the app! Another suggestion is to swap out the stock antena for a larger one.