Just Cause 2

This achievement should come naturally when playing the game. If you should however be looking for specific vehicles then please have a look at the solution for Trying Everything Once in Just Cause 2.

Unfortunately the map seems to have stopped working. I'll leave the link in the hopes that it may work again some day: http://www.maplib.net/fullmap.php?id=8630.

Review 14 March 2016: Added noformat tags and corrected spelling.
Review 24 September 2014: Invalidated map link.

You'll get this achievement quite quickly. There are more than hundred different vehicles in the game, so it's just a matter of short time before you'll get to ride 30 of 'em. To speed the process up, just hijack about every possible ride you see. The game tracks your progress of unique vehicles driven, so you can easily see how many rides you've allride drove.