When I purchased E60, I was told it was Sirius ready. Come to find out it was not. Decided to get an XM 2 Go portable, and would now like to wire into radio. Is this DIYable? Any thoughts would be appreciated. Thanks.

You would need the dealer installed "Aux input". It costs about $250-$300.

You could always try the Delphi MyFi which has an FM transmitter. Not sure if it would work all that well in an E60 (as radio reception in the E60 isn't a strong point) but might be worth a look if you can try a demo model and see how it works out.