Sorry Kyu, but it's well and truly possible to get 6 stars on the second.
Don't beleive me?
Go buy a rocket launcher and sniper rifle (body armor is a plus). Excessive rounds for both. Go to the multi story car park, all the way to the top. Run ontop of the ramp that you can jump off, then Very carefully jump up onto the ledge, look down. Then jump back down onto the ramp (forces the cars on the road to be drawn, and targetable).
Once you have that setup good to go, start sniping. Rocket launcher brings it up in a hurry, but it's fun to snipe. Lobbing a few grendaes is ALSO a bonus, as it will hit the cop cars right below you.
In particular, you want to hit the chopters. Those things are vastly annoying, but once rocket and they go up in flames. Just sit back, blow every car you see to hell, or snipe on the citizens. Takes about 5 to 6 minutes to get 6 stars, depending on your kill rate.
Thenif you are REALLY tallented.. you can pick up a tank. Honestly I suggest using the anti agro code if you want to do that, and instead of getting ontop of the building to do the killing, get in the BOTTOM of the car park.. get yer stars up to 3 outside of it, the scope rifle does great for this, as well as the rocket launcher. You're going to take some hits here, but as soon as you get 3 stars, DO NOT exit the doorway - for whatever reason, as long as yer inside NO cop cars will come in. Step out, they swarm and will enter the building, which generally results in you dieing. Once you get 6, run outside for about 3 seconds then RUN back in. As soon as you see or hear a tank, do the agro kill command and run out.. try and jack the tank.. it's dificult, but doable (the US Army folks are good shots with their rifles).
It's realitively easy to get a tank in the 3rd island also.. just have to stand between the small wall and the road next to yer hideout, and get to work.. it will hurt a bit, but still possible. Again, if you try this, be ready for a while of headaches if you don't try and de agro first.. as soon as you get into a car, all it takes is for a slight TOUCH of a tank on yer car, and you blow.
~Akaran.
GTA3 madman... I find a great deal of fun doing nothing but setting random hookers and gang members on fire.
edit: Couple more things about tanks. Once you get yours, the following are BAD THINGS:
-- The cannon, while having infinate ammo, doesn't have great range, but you can rotate it 360 with the second joypad. It ALSO is the MAJOR way to get stars while driving a tank.
-- Once you start indiscriminately killing people, DO NOT STOP MOVING. Here's the cute thing.. EVERYONE will try to pull you out of your tank. Hobos, hookers, wandering idiots, cops, everyone. You just became the big bad super threat, and everyone wants to be a hero.
-- You are, for all intents and purposes, indesctructable. Bullets can't touch you. Cars will detonate if they hit you with any decent speed. About the ONLY way to die from this is to TOTALLY have cars ramming you every second for 15, 20 minutes, OR getting flipped. Tansk are VERY damn hard to recover from a bad spin, and once in a while you will get launched if a low profile car hits you head on.
-- You can get a tank into the garage to save. It's a HYPER tight fit, exp on third, but it's doable.
-- You go up hills slower than old arthritic people hump. Expect it.
-- Damn turrt can not be aimed up or down, just 360, goes straight out and blows at a certain range.. most of the time you'll be blowing up yer target from proximity damage.