Line In for auxiliary input?

is there any way to add auxiliary input or line in of any sort (rca or 3.5mm) so I can hook up my ipod to it? I don't think there is any ipod interface either, so I would be happy with a line-in.
Thanks!
If you are looking for something relatively simple then I suggest you use a cassete adapter and put it in. The door will close with a little prodding and just hook the adapter to the iPod headphone out. This is what I do and no problems.
As alternative, are there any direct replacement radios? like from later models?



