From Before I Play
- Gather the agility tokens you find on roofs and such. You can travel much faster.
- If you want to level up driving you're going to have to cheese it as the game sucks at giving it to you through natural play. Don't worry about it too much though because you're probably NEVER going to be in a car as its faster to free run across rooftops.
- The easiest way to level up driving is by ramming people. Doing the racing missions is too slow. The 2nd island has tons of guys who stick to the ground (the 1st island has too many enclosed areas and by the 3rd island enemies stick to rooftops). I fully leveled my car in 10 minutes by doing the final "cleaning" missions simply by ramming half the enemies that show up at city hall or whatever then waiting a minute for them to respawn.
- Sniping people from the rooftops builds your agility as well as your gun skill. Don't shoot people from the street if you aren't maxed out on agility yet. Agility is possibly the most useful of the stats, since it lets you fly around the map quickly, jump really high, and climb buildings easier.
- The final assault of the final boss is a huge pain in the ass. The building is a bitch and a half to climb, and I'm pretty sure you can't get all the way up from the outside. The fight itself is stupidly quick, though, especially if you just punch him in the face so hard he goes flying off the side.
- To level driving skill (And you should, since the Agency car gets guns at Level 4), I found going berserk is the fastest way. Get a hit squad after you, and then drive around that particular island running over everybody. Literally everybody, like driving on the sidewalk. The hits you take to your levelling by running over pedestrians are more than made up for by running over gang members, and on the highway (remember to stay on your island although sometimes the hit squads carry over to the other islands) if you stick to driving on the wrong lanes, the gang members in their oncoming cars should die instantly if your speed is high enough.