I had mine basically working but nowhere to really put the empeg. In the end, I went and did this instead.

Probably better really. I did lose the speed dependent volume and it's not quite as loud as it could be, but I can probably get that speed dependent volume back if I figure out OBD2. The pulse signal is right there so at worst a small micro could do it.

If I had an E46 I'd hopefully have navigation with the LCD/TV. In that case I'd be building a full car PC instead. I'd have a car PC now if there was an easy way to fit it in an E36 without losing the onboard computer and without covering the middle air vents.