I really didn't to pay sony $100 just to use aux in as well but I was forced to buy it. ;( I looked around. Its more then just an electrical singnal, it needs specific signals. If you seach good there are people designing hardware for it, but by the time you bought all the tools and put in the effort you'd but at $100 or more. Also i've heard that many people have fried their cd decks trying it. I don't know about you but I'd rather pay $100 more then frying my $300 m610.

-Greg