[nomiS330d]

I've just received a box full of all the rear suspension arms to go with the outer control arm bushes i've already got. I'm now thinking of dropping the whole subframe out when i do the arms and bushes as it will be easier to do the job. I'm now thinking if i do that i may as well do the subframe and diff bushes while i'm at it.
Do M3 bushes fit as a replacement to my 330d bushes and is there any benefit to doing this?

[nomiS330d]

Or just polybush it? My concern with polybushing is noise. I already have powerflex inserts in the mounts which have made a difference to the amount the subframe moves but they have created a noise at certain RPM's which is annoying.

[Tambohamilton]

Definitely fit m3 subframe bushings. That'll give the biggest improvement of the lot. It's a pig of a job though, so make of that what you will. It'll definitely be easier with the subframe out from under the car. To block the brake lines when you disconnect them, just keep the brake pedal pressed. And maybe even consider tyre soap as install lube for the new bushings (do your own research there - it's just an idea!).

I wouldn't fit pu bushes...ever. But that's just me.

[nomiS330d]

I am thinking I’ll drop the subframe to do the bushes and arms all together. So M3 ones are the same diameter and will fit?

[Tambohamilton]

Yep, direct fit. Observe the m3 mounting instructions though, regarding rotation etc