Cruchfield has the US -> Euro adapter for between 5&7 dollars.

As to popularity... The empeg was and still IS a great success. The 'first run' companies that break ground almost NEVER manage to stay afloat. Products die and are later reborn (often in different packaging) when there's greater consumer knowledge. Empeg broke ground, clarion, pioneer etc.. are just following in empegs boot steps.

A consumerized version of the rio-car would sell very well these days. Something between the pioneer unit and an empeg.....