This post needs concluding after being open for quite a while. My customer has after some explanation and attention decided to live with the Toyota and its quirky rpm control. I found no faults with the car or anyway to improve it.
In the meantime I have not had and other models in the workshop as a comparison. I do not know if the Toyota dealer can improve the software.
A very useful topic board in the future could help members out dealing specificaly with reflash cures.
I know this would be difficult but imagine the time it could save if we had somewhere to look listing the software updates that were known to cure specific driveabilty issues. It could never be an exhaustive list of course but it could help. Especialy as a group our knowlege overlaps, as we are all stronger on some manafacturers and weaker on others.
Thanks for your replies.