I have just watched a review of the standard fiesta on what car's website. They did a section on practicality, and in the video showed a picture of the rear seats folded totally flat. The base of the seats had been lifted foward allowing the backs to fold totally flat into the floor.

I have moved countries and helped my bro move into university and never knew it did this! The amount of stuff I could have got in it if I'd known!!
Has anyone actually done this with their seats?

Yes, I have when buying some furniture! Was a pain in the ass to put back tho.

Yep I've done this countless times recently too. I had no idea until shortly before National Day!

no never done it and not going to! don't put anything in it anyway!

I have just been outside and done it and found it really easy to do. There are little clips on the backrests to clip into the seat belt clasps to stop them falling under the seat.
Strange that I have had two STs in the space of two years and only just found that out

Yes many times when ive needed to carry anything. It was in the manual I think but tbh I thought it was fairly obvious...

Well not to me
And read a manual? You can't be a true bloke if you do that