my car has 260,000 but runs perfect.but gettiong on the highway at 55mph + the rear end feels loose....like it sways back and forth....i was thinking it may need some $30 bushings but if thats not what it needs and its gunna cost alot then i may sell it...does anyone know what the problem may be?

Sounds like either subframe bushings or the rear trailing arm links (aka. dogbones). The dogbones are cheap and easy to do, so I'd try them first. The subframe bushings aren't much more expensive, but it's a lot more labor.
Good luck

Sounds like either subframe bushings or the rear trailing arm links (aka. dogbones). The dogbones are cheap and easy to do, so I'd try them first. The subframe bushings aren't much more expensive, but it's a lot more labor.
Good luck

spot on, and go for the dogbones first. My e28 liked to get it's ass out and it was quite scary when it was raining and at high speeds. I replaced the dogbones and it's a million times better now, although I still have to replace the damn subframe bushings as those are shot too. Sigh, it never ends lol.