Neonlow
Your problem sounds very different and suspension or engine/gbox mount related
A few Stilos have had steering rack failure
With a rack and pinion steering rack,
when the pinion gear loses a tooth the steering starts to move and then jumps back as it jumps over the missing tooth with a loud clunk, in the same point on the steering wheel rotation
If the gear is worn excessively or all the teeth are stripped then there is no connection to the wheels and the steering wheel just spins with no resistance. It would feel much the same if the steering column became detached from the rack at the column connection shown in top photo
Recall details here
http://www.vosa.gov.uk/vosa/apps/recalls/default.asp
The recall advises rack preload adjustment OR rack replacement so it depends what they did at the time. If the rack wasn't replaced and it's now failed then there may be a case to answer