I just downloaded this rom from an imported US car and have no idea how to read it... Any help much appreciated.

 

This shows up as a 96940011 (evo 8) rom, but the tables aren't in the right place. I've done a bit of disassembly and it looks the same as the 88590015 (evo 9). I've hacked up this xml file which should let you edit the ROM just fine.

Put both these files in your ecuflash rommetadata directory and try opening the ROM again. Please let me know how it goes.