I have two Linein plugins for Winamp.
One I used with 5.5 is called NullSoft Linein Plugin.
The other is Linein Plugin which the published in 2001.
I can no longer find the Nullsoft LineIn plugin and the older one seems to be the only one available from the Winamp site.
I am using Winamp 5.6.
"Did you test it in carwings??"
Sun, Come shine my way
May healing waters bury all my pain
Wind, Carry me home
The fabric of reality is tearing apart
The piece of me that died
Will return To live again