Adding cars:

First create a car description file TheNameOfTheCar.car

In this description file write the following info each on it's own separate line:

image filename (the path of the image associated)
top speed
deceleration
torque
grip

To make the car show up in the game you have to add TheNameOfTheCar.car into cars.list on a new line.



Adding tracks:

First create a track description file TheNameOfTheTrack.trk

In this description file write the track data. All tracks are 6*5. I've found it easiest to start with a clean slate:

000000
000000
000000
000000
000000

Every track has to have a start, this is signalled by a 7.

000000
000000
000700
000000
000000

From here on out, the track will start building itself to the right of the start tile. If we wanted to add a piece of straight line after the start we'd just set the corresponding tile to 1, the value of horizontal straight line.

000000
000000
000710
000000
000000

The codes are as follows:

3  1  4
2  0  2
5  1  6

0 - empty
1 - horizontal straight
2 - vertical straight
3 - bottom to right or right to bottom corner
4 - left to bottom or bottom to left corner
5 - top to right or right to top corner
6 - top to left or left to top corner

After filling out the data so that the track forms a closed loop we'll just have to add the track filename (TheNameOfTheTrack.trk) into tracks.list on it's new line.