Gave it some spray grease today. Can't say that it's made any difference really. What I did notice was that it doesn't do it when the engine is off

As for the knocking. I bought the dog bone stabiliser from Fiat for £24, got the car up on axle stands this morning but I wasn't happy with the stability of the car. I couldn't get the bolts undone so I'm off to a local trusted garage this afternoon and he's going to put it up on the ramps and have a look. I'll get them to do it and get a second opinion on the fact that it is actually that that's causing the knock as it looked in good condition as far as I could see.

Fingers crossed!