Any time there is more weight than just myself in the car during acceleration or traveling uphill at a steady speed I get a buzzing rattle noise that seems like it is coming from the rear of the car. Any help would be awesome. Ive owned the car since 1996 and do all my own work on it...

 

Welcome to TMS! Have you had it jacked up and checked around under there yet? I would guess maybe exhaust is loose somewhere

 

Also check your u-joints, and the bushings around the rear axle