This mod will make cars flip around crazily like in GTAIV carmageddon mod. Make sure you back up original handling.cfg because you won't want to keep this mod on forever it hasn't crashed my game at all.
To make cars flip you can do these things: blow it up, touch a car..if you get in a car(which you can) it will jump and most likely land on it's wheels..the only cars not affected are the cabbie and idaho(the cabbie handling is a little off)... the ambulance and firetruck are mostly affected.
Installation: you can replace the original handling lines on any car you choose with this 100.0 0.8 1.5 1.0 0.0 0.0 -0.1 70 1.10 0.75 0.50 1 75.0 35.0 4 E 5.5 0.50 0 25.0 1.6 0.1 0.2 1.0 500 0.28 -0.08 0.5 0 0 1.
Back up the original handling line... you place this in: my files/device storage/android/data/com.rockstar.gta3/data... open handling.cfg with a text editor and delete any cars handling line and paste mine..and save..then open game... remember to back up handling.cfg!
... I have an android so I know nothing about PC version..have fun