Thanks guys.
Trucker_Jo, Thanks for the link! I will have to spend some time looking at all the stuff on there. I don't think a line machine will be my next project but it is on the list and not too far down.
I spent a while trying to get the sound unit to be less 'idling or pinned'. It's a bit of a challenge because the sound unit motor always takes the same amount of throttle for a given rpm where as the truck always varies based on load. I did manage to improve it slightly and I think I am just going to have to be satisfied with how it works. I need to keep in mind that this was something designed for a small kid and a bicycle, not to replicate the sound of an Off-highway Kenworth.
http://www.youtube.com/watch?v=ep7Ub...tJ-DusnO8Onw7A
The onboard shot picks up a lot of background noise from the driveline and also it was quite windy here today. I think if the camera was actually in the cab instead of behind it on the water tank it would sound pretty cool.
http://www.youtube.com/watch?v=kCbCD...tJ-DusnO8Onw7A
Thanks for looking