Auch wenn ich mich schrecklich blamiere:
Hi!
Nice to have you here! I cannot answer much questions but the following:
Starting with MY 2007 (from autumn 2006), the Germany Legacy has air condition which can be adjusted for 2 passengers.
This is a picture (taken from subaru.de)
I have not heared yet that dealers have many parts to allow other sound systems. Most changes were realised by the work of the owners. As the sound system comes from Kenwood orginally, there are some parts available.
With best regards
Alex