I tried searching the archives, but did not find anyone who had actually installed the Audiovox "Rostra" CC on a Valk.
I just searched using "Rostra" a ton of info is there from member Friagabi. Most of it is around 10/07. Rostra CC
is not Audiovox they're proprietary to Rostra Precision Controls, Inc.
The Old Tech Archives & Google are your friends. It helps to make use of them and can actually provide more info in addition to what can be obtained here with a few thread responses and enable better decision making.