Audi shop in Portland, OR?

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Hello,
I recently purchased an 95' Audi 90S Quattro.  I'm looking for a recommendation to a respectable and trustworthy shop that's local to me here in Portland, OR.  I'm wanting a complete look through on it, then help getting it to where I want it performance wise.  Can anyone recommend a local place? So far "Matrix Eng." has been recommended to me, but I want to check out more than one option. 

Thanks,
Sandy