Swede, we should meet up and compare noises. *s*
The clonking sound might be slack in the belt being taken up. Alternatively a loose bevel box. Check for moving petrol tanks, too.
If it is a rattling sound check if the roll over bars touch the aluminium body. In mine it isn´t the petrol shut off valve that rattles.
Etc, etc....
It is when your car is quiet you should worry, then something probably fell off.
