If you were not 5000 miles away I would be all over it.
I think that might be the challenge. Focusing on Subaru's gives you a niche, but your customer base is spread out because not everyone is building Subaru's to your level of quality.
I think that is probably why the big custom fab, performance shops specialize on multiple platforms so they can distribute their quality seeking customer base among more customers, I imagine the platform has a lot to do with that too, you don't see many low quality parts on Porsche's, or GTR's. Or maybe you just never hear about those guys =)