Thanks for all of your replies!
The car has been in at my local dealer (Guests in Solihul), and I've since had my rocking seat fixed
My squeaky seatbelt still remains though, and I'm not sure if they can fix it. I don't think it is the seatbelt rubbing against the leather, as when I firmly hold the entire seatbelt clasp the noise stops. It appears to be the vibrations of the road causing the squeak.
I had a 147 1.9 JTD Turismo for the day as a courtesy car, and the seats in that are sooo much better than that of the Brera
You sink into them and they are instantly comfortable (I still haven't found a seating position in the Brera I'm completely happy with), plus I didn't hear a peep out of them and they didn't move and jerk around which I have become acustomed to!
My car is back at the dealers next week for further small jobs. They replaced my PAS fluid, and now the horrible early morning power steering problem has seemingly disappeared. Added to that they have ordered a new PAS fliuid reservoir under warranty.
They have also ordered me some new alarm door sensors which should fix the random alarm going off. I'm sure the neighbours will be happy about that too.
They also did a superb job refurbishing an alloy for £78, which was quite badly damaged - I didn't think it could be repaired! I have the multi-spokes and I kerbed it on a metal lip at a petrol station, and a huge chunk was sliced out, it was quite a state. But they have a guy in on Tuesdays, he's very good and my alloy looks brand new!
I took their top engineer out in the car so he could listen to the squeaks and creaks, and he explained to me about the 2.2 JTS hesitation issue (the thread is so long on here, I get a bit lost reading it to be honest!). He says the problem is that the engine effectively does not have a choke, like older cars would, and not enough fuel gets pumped into the engine. He told me Alfa are working on a fix for the issue which could mean all 2.2 engined cars have their ECU's reprogrammed or something. I guess all we can do is hope on this one!
One annoying thing has happened since the rocking seat was fixed though. The whole seat would have been taken out and I think they dropped a screw or something inside the seat, it appears to be inside the headrest! Now, whenever I turn sharply left or right or go roaund a roundabout, you can hear the sound of a screw darting from one side to the other inside plastic!!!
Oh well, another thing on my list (I've now got an Excel spreadsheet to keep track), and she's in again next week, so looks like one of their techies will get another trip out!!