Wifi backup camera on excisting wifi in car

Is there a wifi backup camera that do not create its own wifi network, but could work on an excisting one in the car? Or have I got this wrong?

Update: I don't think it is possible, but I'll keep looking for a work around.

Anyone out there using a wifi backup camera that can shed some light on this?

We have an Android navi unit in the car. It works well, but we use iOS everywhere else so it would be nice to have an iPad Mini in the dash instead. But... that would do away with the backup camera which is really nice to have on the Prius (as there is no video input on the iPad).

Then I thought there must be some wifi solutions.
But they all look like they create their own network and you don't want to switch network to back up when you already have your own connected to the internet. Our car has a Huawei E5372 4G Mobile WiFi glued to the windscreen behind the mirror.

I found this app that looks like a dedicated wifi backup camera parking app. There are probably lots of others, but it looked nice and was quick to start. Unfortunately it is in Chinese, at least on iTunes and on the net where it is sold with a backup camera.
V·手机倒车 - 全球首款手机倒车摄像头 til iPhone, iPod touch og iPad fra App Store på iTunes

Would be nice to have a backup camera that was avalable on the cars "own" network