Anyone got any ideas ?

Finished work drove to supermarket parked on a slight slope, went to start the car and it made the most horrendous screeching noise meatallic shearing sound when I turned the key. Obviously I stopped truning it over straight away checked everything over. No visible signs of anything Then re started fine, drove for another 2 miles all good.

Seems strange that it's done it after an oil change or it's just pure co incidence, starter motor on way out ?

I'd have to say the starter motor mate if it didn't start when it did it. 

Almost like a clutch was engaged and trying to pull its self out.

I'm off to check the oil level in a bit so I'll turn over and see. I did remove the belt cover to get to the crank sensor so maybe something was catching

Yeah does sound like a starter motor going. 

yup sounds like the motor spindle didnt fully engage / pull all the way out

Pleased to report that it's not done it since so hopefully it was a one off

Well hopefully just a onr off for you mate :-)