Ground wire connections and cruise control

I have 2 questions concerning my 1998 VW Cabriolet and I hope someone knows the answers. They might be related.  
I thought my old factory radio was shot (as it turns out it was) as I was getting alot of static and hearing the click,click,click on it whenever I was using the turn signal indicator. New radio and the same old sound. I would like to see if my ground connection is caput. Where is it?
Secondly, and more frustratingly, my cruise control is intermittent, more off than on actually, and i'm wondering what I can do about that? My regular mechanic can't seem to find the problem and I really don't want to have to go to the dealer.