CDR-220 Grounding Problem ???
 

My 2002 boxster has a problem during summer in NM--sounds like the typical spark plug wire "SUPRESSION" problem in the 70's--anyway, when the car hits a bump the left AM/FM/CD speaker channel , starts to amplify the spark plug noise--strangest thing in a such a fine engineered automobile...reallly sucks--it's on the driver side!!!
update:
ONLY LEFT CHANNEL--it's so annoying on a normally good sounding system...thanks!