I have just priced up the SUBARU fitting kit to convert a double din dash to the same spec as mine, it includes the complete new single din facia panel and the radio mount. £70.24 + Vat.
The SAT Nav is priced at £595.00 check with your dealer, part numbers are
Nav Radio H001ESA010
Conversion and installation kit H0010FE000
The radio fits from MY05 and also the latest 2.5 version too.