My ST170 has developed a rattle which is coming from the gearbox linkage (the part inside the centre console in the car). I took the cover off to have a nosey around, and I spotted that a bright orange circular clip had broken off (it was just lying there in the bottom of the car), I've no idea where it came from and after having fished it out to keep in a safe place had a clumsy moment and dropped it back down into the hole where the gear linkage is and it has disappeared! I assume it's an important part otherwise I'd have had no problem holding on to it!

Does anybody have any tips on:

1) Making the gear linkage a bit smoother
2) Where this orange clip came from (circular with a thicker bit and a gap on the thin side)
3) How to resolve the rattle. It only appears in third gear, that's also the only gear I can feel movement in the gear leaver. The gearbox still feels strong so I assume it's not excess vibration from there, it only happens at low revs under load too.