There are a few (four to six) westerner-run brokers in Tokyo who will do the whole thing for you, including sourcing the vehicle at the out-of-town auctions. They do a lot of exports so you'll get the economy of scale in managing the shipping / paperwork etc.

Unless your stepfather is familiar with Japan and speaks pretty good Japanese this is the only way to go. If not, then trying to do any part of it by yourself at the Japan end is a sure route to ulcers. Can't speak to the ease of doing it at the European end.

These are probably the three brokers that get most coverage / buzz in the market here. Never used any of them myself so can't give an opinion.

http://japan-tradings.com/index.htm
http://www.occidental.co.jp/
http://www.micklay.com/

Regards

Mark