Purchasing a car abroad.... to drive home

[MonzaEvo]

We're about to jet set off to europe, and after getting stuck during the xmas eurostar disruptions and the recent 'cloud' issues.... it got me thinking of contingency plans. Now, the idea that Bill Bailey seems to have had (Citreon DS, road trip back through France) is appealing

But... what are the logistics of this? How easy is it to purchase a car, register a car, and insure a car whilst in a different country with the idea to drive it home