Unfortunately you have the video set to private, so we can't give it a listen!

To me... It sounds like a bad pulley or a bad catalytic converter. Either way, it's worth some investigating.

I had a squeak / rattle that was due to a loose nut on the downpipe exaust bracket

Thank you all for your responses, I'll look into both of those suggestions.

Could be either of those things. Sounds like a pulley noise, but could be a chirp of metal ehasust components rubbing together. Get a mechanics stethoscope (they're cheap) and touch it on each accessory with a pulley while the engine is running (very carefully). That's how I figured out my alternator bearings were making noise.