I used NYK's RoRo "Asian Pendulum" service, which runs approximately every fortnight. This vessel circuits SE Asia, and calls at Jakarta 2 days after leaving Singapore. (The same vessel also calls at Port Klang in Malaysia, but the journey time from Port Klang to Jakarta is 2 weeks.)
Check the NYK website (www.nyk.com) for details. The NYK office in Singapore is efficient and friendly. Book your space with the RoRo desk (+65 6292 4342), and then appoint a shipping agent.
Leaving Singapore is just a case of taking your vehicle into the port with the shipping agent. You'll need a port pass (S$2), which the agent will arrange.
Have your Carnet stamped.
You now need to revisit the LTA on Sin Ming Drive to close your AutoPass. They need to see your Carnet with the exit stamp.
Getting a vehicle into Indonesia as a temporary import by ship is not as easy as with most other countries.
See the Indonesia country info section for information regarding required paperwork and authorisations.
For some general information regarding shipping your vehicle, refer to the "General Notes" section.