Is there any way to check which anti roll bar I have on the car???
I don't think you can see it easily, but the original is a pretty regular shaped ARB with rubber bushes about 1/4 way along the bar from each end. The problem is that with wear, the bushes slide along the bar slightly and the bar becomes slightly displaced (not dangerous - altho not working to it's full potential either and squeaks like an old mattress). The new one has stoppers welded on to prevent the bushes from sliding. I would have assumed that the newer item is on your car. A mechanic at the dealer should be able to tell you.
i have the same problem with my 147 > my mechanic had a look at it and said that it was an old "heat shield" > wear and tear causes it to become soft and vibrate > usually happens on take off and/or on a hill start.
> i don't know if it would be worth replacing it with a new alfa heat shield coz you'll have the same problem > it might be worth replacing it with an aftermarket or moulding your own.
In the dealers today and they have diagnosed the fault with a little help from me that the noise is coming from a bearing in the steering column so they have ordered a new one so hopefully that should be it !!!