In the upper screen within the rev counter I can get it to show the current speed, if I scroll through the computer options and leave it on current speed. However, when I cycle through the other options it then removes the speed from the upper screen and replaces it with time & temp.

I have borrowed a couple of courtesy cars whilst mine has been in for service (both newer than my 08 plate) and they both have had the speed shown in the upper segment, regardless of what you display in the lower section.

Is this something that they brought in for newer models, or am I doing something wrong?

Yes it is a newer model feature. Our 2011 shows speed at the top all the time and you select the other functions in the lower section. Our 2007 functions the same way yours does, personally I like the new way better.

Thanks, that explains it. Shame though as I think the new system is much better.