The PC version of Grand Theft Auto had the vehicle specifications stored as plain text files. This meant that you could load them into a standard editor and change their handling. You could adjust many areas of the vehicles' dynamics from weight to acceleration, turning circle to strength, just by changing the values that were already there.

Once you have played with the cars you can also move onto the maps themselves. It took me a while longer and a bit more experimentation, but I soon found I could add power up crates to the levels to make it easy to pick up a rocket launcher right away, for example. Just remember to backup your data files before you start.

GTA is such an open ended game that you can get hours of fun out of it anyway, but when you discover you can create an almost indestructible taxi with a top speed of 400 mph and instantaneous acceleration you start to realise its real potential.