I have a level 2 MusicarNW system in my wagon.
If you want to come by and have a listen that's OK but I am in Santa Cruz.
I have an xd600/6 with Morel Dotechs and Jehnert underfloors.
PM me if you wish to do this.
If you read my installation procedure I make some comments about the
way it sounds at various stages of installation .
the procedure is in
http://www.e90post.com/forums/showthread.php?t=641323
in the Hi Fi section.
The musicarNW packages are in that range .
You can do it cheaper but you have to do a lot
of work to gather and integrate the pieces and I don't know it that ends up costing you that much
less anyway.
When I was checking out what to do I ran across a guy that had a level 1 system essentially and he had a L7 system in his previous car and he commented to me that the level 1 system he had sounded better than L7. (diamond audio door speakers SWS8 floors and a xd600/6.