Mongolia isn't difficult to drive into - the border crossings are decent and safe. You only get problems when you are importing your car there. Not sure about the carnet de passage situation there which can be expensive (even if you are not leaving your car there, you still need it, your car is classed as "imported")
As for the other countries, the Visas were simple really...I think the Russian one we had to translate though. Border crossings were fine apart from the odd bribe. In Kazakhstan you have to register your Visa within 5 days of being in the country or you could in theory be deported. In Russia they will probably tell you that to pass the border you need insurance - but dont take their word for the price they give you!
Remember that if you leave a country to go back in, you will need a double entry Visa. Make sure you always get Visas stamped or border officers may not beleive where you have come from and get irate.
"Vehicle Passport" means our V5...which a lot of police/borders will want to see.
Regards
Alex
Probably looking to do a return trip to Mongolia in a few years as we enjoyed it so much.
