I couldn't manage to put the ATX and GPU cables behind the motherboard tray, but they're clamped to the front and because the fans are 180mm the cables don't interfere much at all.Do love the case though, the filters is a bit plus for me that i can just remove them without having to take things apart. Just felt like i was working in a mini/micro atx case working cables instead of a mid-atx which wasn't surprising just felt like it didn't have to be so because you'd want to avoid laying cables in the path of those nice 180mm fans.
IMHO the FT05 has two major design mistakes: firstly the PSU should be on the other side of the motherboard, as with the FT02, and secondly there should be about 1cm extra room behind the motherboard tray so cables can be easily routed.
The reason for moving the PSU is improved cabling for the ATX power and the 8-pin CPU power cables, particularly the latter. Right now the CPU power cable stretches right across the back of the motherboard, and is impossible to change without removing the motherboard.
Edit: I've just thought of another good reason for moving the PSU back: the USB and other connectors on the motherboard are generally on that side of the motherboard, so you'd save more cables stretching across the back of the motherboard.