Ferry. The race is broken up into liason (non-timed portages, if you will) and timed specials. They are only on the road 8-18 hours a day. It's not as if they drop a green flag in Lisbon and the first one to Dakar wins. ts much more heavily organized.
All cars must be road-legal and registered for travel on all the roads in each country they visit.
Sorry, I'm used to NASCAR and Indy where the green flag drops and you race until something blows, you end up in a fireball, or someone gets the checkered flag.