In the end I got an E2 to use with my PC. You have to install a Meridian USB driver on the PC. I was told by my dealer that there is no such driver for an iPhone or iPad so it won't work. As for using it in your car, I'm not sure but would there be a way to install the Meridian USB driver into your car system?
Meridian once suggested that Explorer should work with an iPhone is connected through the camera connection kit (CCK?). I think someone tried and it worked although iirc needed a powered hub for power.
However, I don't think the camera connection kit is a viable product anymore due to the demise of the old style connector plus there seem to be different versions of the CCK (when I plugged mine into my iPad 3 it said that mine was not a supported product which, although an official connector, was purchased in classic iPod days). I don't know whether the more up to date alternatives would work.
This is a
link to the lightening based Apple CCK. Compatibility with cameras seem to be a bit hit and miss let alone with non camera devices. But if there was a non quibble returns policy when buying, I guess its worth a shot although the need to use a powered hub would seem to make its use as a portable device somewhat limited which, as the item linked only seems to support iPad, portability may be less of an issue.