I finally got my computer to run in my car ...and to transfer sound to my approx. 2 years old headunit( has no input rca's) i decided to go the easy way for starters and bough a "tape thingy" that allows you to get audio input via the cassette part.
What i hadnt thought of, or remeber seing here, is the tiny detail that my headunit is "inteligent" when it comes to cassettes ... i.e. it flips sides it self, skips blank areas and let you skip numbers.
unfortunately the headunit think that it has to change the direction when using the "tape thingy", and will contiue to do so 4 times until it assumes that there is a fault on the tape and stop trying ....
So think of this when you are searching for a solution of audio inputs.
I will be calling the manufacturer and ask them for advice, but expect they will advice me to buy a new head unit
headunit brand is Kenwood, model 657
So be aware