Google calendar & iPhone - bidirectional sync

Hi.

I use CalDAV protocol ("Add CalDAV Account") to sync bidirectionally events between Google calendar and my iPhone.

Is it also possible to bidirectionally sync a subscribed Google calendar ("Add Subscribed Calendar")?

The reason why I ask is, that I have about 15 caklendars to sync on one iPhone. When I send the http://.../basic.ics link to m iPhone e-mail accound, I can simply click on this link in order to include it as subscribed calendar to the iPhone. This is very fast! Drwaback ... it's read only. Hence I can't create events on the iPhone on these calendars (= no transmission of events to Google).

CalDAV does allow creation of events and subsequent transmission to Google, but it's setup is way more time consuming.

Any ideas ...?

Thanks,