Unity iPhone - transparent background, native UI bleed through

In our iPhone app we manage the background through native code, as well as other parts of the app. Is there a way to have unity not render a filled background so we may have out native ui bleed through? I have tried depth only camera (produces something similar to no clear), setting solid color transparency to 0 (ignores this value) with no luck. Your responses are much appreciated!

Would also love to hear about this!

anyone? I got same issue...