It's been a long time since I posted about the V50 and it is because I haven't done much to it.
It still has the check engine light on due to a variable valve timing fault.
I tried changing the oil to an A5/B5 type oil to see if that would fix the issue, but it made no difference.
Not wanting to spend a lot of money on a guess that the fault is caused by the VVT solenoid, I have been looking around for a second-hand part but haven't found any.
I found a new part on Aliexpress for less than A$30 shipped so I ended up ordering one of those and am waiting for it to arrive from China. I'm not expecting OEM quality, but at least if it solves the problem for a short time then it will have done its job of helping me diagnose the problem.