Countries in 24 hours

[Hammer]

Start off in Southern Mexico and I reckon you could do a canny few heading towards South America.

Central American roads aren't great, especially if you're trying to go by any sort of direct route between countries, and even the Pan-American Highway ends when you get to the Darien Gap. Plus border crossings can take a while. Europe's definitely a better option.

 

[Its Him Again]

I did uk , France, Holland, Germany , Austria and Germany.
Was absolutely fucked driving .

 

[riffraff]

19 by driving. Start in Greece finish in Lichtenstein. 23hrs 37mins. Dont think the numbers can be beaten but the time probably could. Twas in 2014 so may have been bettered. Google is your friend. Some flights....the cheating bastards! As you were.