The Chinese version of the Huawei site has the following ROM listed for the G300, however, it's for the Chinese version the U8818 NOT the EU U8815.
From this page:
This should go to straight to the 3rd tab called '下载' (download).
The direct link to the ROM is:
Does anyone feel brave enough to flash this onto their U8815?
WARNING: Apparently it is working but not recommended as you will lose android market access. This is not permanent and the phone can be flashed back to a stock U8815.
Thanks to 'Hans Gruber' - Original post about U8818 rom is here:
Edited by t-bon3, 01 June 2012 - 08:44 AM.