2002 Chevy Malibu 2002 Malibu rear strut mount

Suspension problem
2002 Chevy Malibu 6 cyl Front Wheel Drive Automatic

ok, I have a 02 Malibu, everytime I hit a bump or ot hole (where I live it's unavoidable)(western NY) theres a rattle in the rear passenger side of the car, I took it to a dealership and asked them what it might be they said it was a rear strut mount, and that all I might need is tightned, so I took it home and tightened it up, but it still rattles, and before I tear apart the whole rear end was wondering if it was even te problem or mabey just the strut retaining nut was loose, if there is one, just to save me time and money. Any info would be awsome thanks