Looked around the web and cannot get a clear answer. I was sure they did but can't find out how if they do.  What doesn't kill you is just bidding it's time.

The rear seats fold in two stages.

Stage 1, the backrest folds down flat on top of the seat base. This leaves a step up from the boot area.

Stage 2, the whole folded rear seat flips on its front edge hinges into the footwell area and flush against the back of the front seat backrests. This gives you less length (now the folded seat takes up space over the footwell, but you get a shallow step down from the boot to the back of the folded seat.

Neither option gives you a truly flat extended boot and both have compromises depending on how much space you need from folding them forward.

Hope this helps. Tom

Current Drive
2011 4.4 TDV8 Autobiography - Santorini Black - Ivory Leather

Previous Drives
2004 Model Vogue Td6 (Touchscreen) - Java Black - Parchment Leather
1994 RR Classic 3.9 V8 Soft dash - Niagara Grey - Grey Leather
1972 Series III SWB Safari - Green (Hand Painted) - Black Plastic

Another option is to get socket set out and remove seats, if extra length required. Heavy beasts though! Previous cars:
S-Max 2007-2013 (only diesel I've had, good car but expensive when diesely bits go wrong, so what's the point?)
Galaxy 2001-2007
Mondeo Estate 1997-2001
Sierra Estate 1993-1997
Uno Turbo 1987 -1993
Fiesta 1984 - 1987
Fiat 127 1982 - 1984

^ Yep, i did that when i had to take a big fridge freezer to the dump and they are heavy especially the double one.

What was worse was that they are quite awkward to get in and out of the car and seemed to have this knack of trying to unfold at the worst time

If I do it again I'll put some ratchet straps round them to keep them closed and to provide something better to get your hands round and carry them with

Having said that, its a pretty huge space anyway with the seats folded  2021 D350 Fifty Edition - Carpathian Grey
2017 4.4 SDV8 Autobiography (2021-2024) - Santorini Black
2012 4.4 TDV8 Westminster (2016-2021) - Santorini Black

And be careful with the folding hinges when you remove the seats. They will happily flip out and scratch / damage anything they can touch! Tom

Current Drive
2011 4.4 TDV8 Autobiography - Santorini Black - Ivory Leather

Previous Drives
2004 Model Vogue Td6 (Touchscreen) - Java Black - Parchment Leather
1994 RR Classic 3.9 V8 Soft dash - Niagara Grey - Grey Leather
1972 Series III SWB Safari - Green (Hand Painted) - Black Plastic

Thanks everyone . The answer is yes they do. No idea when I tried when I first got the car it wouldn't budge but is OK now. What doesn't kill you is just bidding it's time.