After all new plugs/wires and having alternator rebuilt noise was still there checked the antenna connection, noise still there, ordered Buick part No. 1224205 $37.36 this is a filter that goes into the radio power lead, and also grounds to the radio case.... noise gone... for all who are having the popping/hissing in my case that was last years problem and new spekers from buick cured that. best of luck to all.