Sorin Grigorean

Hi My names is sorin , and I have an Audi A6 2008 , I don t know how to start ... I had a problem with car and wont start , I call the recavery and they try to start my car , he check all the fuses and hi took the batery off , after the radio stop working and a message come up like ( An installd component is not valid . Please contact Audi Workshop. The get me to official Audi work shop , I fix why the didn t start , is was about 300£ to fix it, no problem , but the real problem comes when they told about the radio , they have to replays something to work and that was 800£ :-o . If this happen to someone please lett me know how i can fix it . Thank you