Maybe it is too late and are you allready in singapore
In 2008 we did the same track.
In Sing go with all your papers to Automobile club singapore (Carnet,international drivers licence, passport and Bill of lading. They give you a insurance (expensive) and temp allowance. With these papers go to the roadauthorities for a tollcard and put there about 10 sing on. You need that when yuo leave singapore.
Even with the tollcard you are not allowed to ride in toll areas, so seek accomdation outside that area.
When you paid the harbour and agentdues to the shippingcompany you can go to the harbour.
Before you are allowed to enter docks you have purchase a entrypass at the gate.
Then show your custompapers and collect your bike.
Before you pass the gate outgoiing the policeofficer stop you and do not allow you on the road. Show him your carnet and Autopass(the tollcard) and wait. Not every day they see a carnet. I had to help the customsofficer.
Passing Tuas, Sing.Malayborder the carnet was again somethimg from outerspace and took quite a long time to arrange.
On the malaysian border simple as biscuit. 5 min to write the carnet in a big book and happy travels.
AA singapore was extreme helpful and I heard they can arrange transport from the dock to the border.
And Sing is quite expensive.