Temporary car import (Seoul)

Hi, if you have temporarily (for under a year) imported your car into South Korea, I'd love to hear from you. I'm looking for some specific answers.

I've driven my US plated 19 year old Toyota 4-Runner almost around the world, and I intend to take a car ferry from Vladivostok to Donghae (DBS Ferry). Their quote is USD $600 for the car and another about $110 for me. Once in Korea, my intention is to drive to a port where I can have the car shipped back to the USA.

Have you ever brought a car in on a ferry (or had it shipped) to Korea? If so, what did you have to do or pay to get out of the port? In particular, did you need to post any type of a bond (to guarantee that the car would leave Korea)? Were there any other fees? Did you have a carnet? I don't have one at this point as I've been relatively north (ie. Europe & the former Soviet republics & Mongolia).

Do you have an agent or shipper that you used to get your car from Korea back to the USA and would recommend? I'm looking at a RO/RO quote of around $ Protected content Korea to California (Port Hueneme) of which $ Protected content ocean freight, and the rest are various fees. But the shipper has claimed that there is no way I'll be able to get my car from the ferry out of the Donghae port and drive it to their port, and I am surprised and skeptical about this claim (and, if true, adds about $700 to their quote).

I'd love to hear about any actual experiences,
Regards from Ulaan-Baatar, Mongolia