Rattling / knocking from under 147
I have a 147 TS Lusso with about 61k on it. I love the car and have never had any problems with it until recently. About 3 months ago I started hearing a knocking / rattling sort of noise from underneath the car (drivers seat or slightly behind). It seems worse when I go over potholes / bumps. The exhaust was knackered and I was waiting for a date with Longlife which I thought would solve it. Once the car had the new system on it I thought it would be fine but it is exactly the same.
Does anyone have any ideas what this might be or how I might sort it out. Any help would be much appreciated. Thanks.