Is this bad subframe bushings?
 

My car has a squeaky bushing sound when I go over bumps, the car feels like the rear is fishtailing at higher speeds especially in the rain, and in a turn when I press on the gas the car bounces and jerks. Is that bad subframe bushings?

sounds like more than bad subframe bushings to me...

is anything done to the car? any maintenance? any aftermarket stuff?

sounds more like a bad alignment and bad lca bushings

or possibly the coilovers(if you have them) or the bushing on the top of the struts are going

not sure about maintenance. only mods back there are megan street coil overs and a welded diff

ok thank you

There's your answer right there. Welded diff? Not streetable! Can't make proper u turns, wheel hop, excessive tire wear, fishtailing, possible weld breaking leaving you stranded. Yeah that's it.Get an LSD.

No I've had a welded diff before and it never did this. all it did was make tired skid when turning but thats it. Definitly not welded diff. all of my friends have welded diff and it does not do this. this is something more extreme.

Were the lca's loosened, loaded, and retorqued? IE: Lowered car on coils, lca bushing twisted to an abnormal position, and are now toast.

Driving with a welded diff puts way more stress on your subframe bushings. I would bet that yours are shot if you've been driving with a welded diff and haven't replaced the bushings yet.

thanks for all the help guys. My plans are now to first get subframe collars then get an alignment done. and if it's still bad than im gonna replace all the bushing in the rear. thanks for the help guys.

not sure if the lca were tweaked with cause I bought the car with these mods.