well, the obvious plug is for han’s VW on 35th. nothing but VW/audi. i’ve used them, and they’re okay. they fit your criteria, but i have a slight electrical problem that they could quite nail down.
there’s also foreign car workshop in the triangle, on 36th, just north of alaska. i haven’t used them, but i think i will next time i need something done that i can’t do myself.
and i’ve heard that west seattle auto works – who have a tile ad 1/3 of the way down the right side of this page – does european cars.