i hate to hog the whole technical forum but i think i may be running into trouble with this car.

i fitted my new 17's on saturday. this morning on the way to work, i began to hear some knocking from the back when id even slghtly press the accelerator. when i got home, i got a friend to bounce the back of the car and if i put my hand on the trailing arm, i could feel the knock.

has anyone had experience of this problem i wonder? i've had suspension knocks/ mounting problems in a lot of my cars but this one seems to have come out of nowhere with no warning. i might be imagining but i think i there's a booming noise at about 60mph.

Yup, from your description, it sounds to me if it's the RTA bushes too. If it is, I'd recommend replacing with Powerflex poly bushes, and once fitted I'd advise getting a 4 wheel alignment done (supposed to after RTA bush replacement).

HTH

I would only go for poly bushes if your going to replace all of them. By fitting stiffer ones in just one place you will put more strain on the others.

This is a well known problem area with the E36 and these bushes can need replacing every 20k miles if you want to keep the handling tight. The parts will only set you back about £15 a bush (25 euros?) but fitting will be 50- £100 a side depending on who does it. A 4 wheel alignment should be done afterwards otherwise handling and tyre wear could suffer.