This issue involves a 2008 chevrolet hhr with the base radio system. the main door mounted radio speakers stopped functioning in 2017. the a-pillar high frequency "tweeter" speakers continue to work but are unintelligible. with the main radio speakers out, two safety features no longer work; the seat belt warning chime and the onstar subscription safety service. i believe both these systems rely on the driver's side door mounted speaker. other safety chimes, if any, would also be affected. this is not an isolated case as i personally know of other hhrs with the same issue.