Would you believe it, I contacted Toyota today to see if they had any specification info they could tap in to on Japanese import vehicles, and blow me they have a department set up just for imports.
I don't know what they do with their time but they were unable to help me with my enquiry, but just in case it works for you here are the contact details
01737 367931
email pid@tgb.toyota.co.uk
Fair do's they were civil and did actually call me back - lots of firms wouldn't bother.