Have you been in a Honda in the last 20 years? The plastics used, say in the buttons, are far superior than what GM and Ford use. Chrysler isn't too bad overall, but we're talking plastic buttons. Design wise Honda's are very ergonomic. Everything is simple and easy to use. Everything is where you would naturally expect them to be. Have you taken a look at the new Hondas (say the Accord) and Acuras (TL, upcoming RL)? They have great interiors. A bit on the techy side design-wise, but it's functional and logical techy, unlike I-Drive and to a lesser extent, Comand.
And the 530i wouldn't run laps around an E320. The 530 is slower than the E39 version and the E320 with the Airmatic suspension actually has great handling.
Here's a pic of the rankings from R&T: