As a similar age/mileage SMax owner who hasn’t done many miles in it since buying it do you mind me asking what symptoms you got / noticed first?
First hint something wasn’t quite right was acceleration not quite smooth, and a little judder around 60 in 4th? Most of my driving is in daylight, and often with sunnies on, so not looking at the dials, so missed the main telltale. Last week coming back from hols pretty well loaded on dual carriageways with roundabouts, lots of accelerations to 70 from 30ish and from 60-75 through traffic. Sit at 60, in 5th, floor it and watch the revs. Should be locked in to increase in line with speed , but you can see the needle spiking up an extra few hundred revs and hear/feel the engine surge without producing acceleration. If your engine revs aren’t getting to the wheels, clutch is slipping. Also, moving off at slow car park speeds, getting quite grabby and jerky, often a symptom of a contaminated clutch. We have had a slow minor oil drip from the area for several years, so was actually expecting not to have got this far without failing.
We’ve had it from 10 months old at 1,700 miles, ex Motability. It had DPF problems from very short trips shortly after we got it, but still in warranty so sorted by Ford, but other than that, mostly trouble free. It’s big and heavy so tyres and brakes might not last as long as you’re used to, so keep an eye on them.