i searched on www.playinginthedark.net but i don't found the information. who can help me?

I got the following  off of that site who knows how long ago, but you should find every thing you need here.
begin info.
This section describes how to build your own vehicles for use with Top Speed 2. All you need is notepad and a microphone to record the soundfile describing
your car in the menu. You can use your own soundfiles for the different sounds of the car, but you can also use the ones already included in the game.
You need to create a textfile with the extension .vhc.
Look at the streetracer.vhc file for an example.
The file contains several variables describing your car. Here's for example the description of the blackbird racecar :

*** begin vehicle file ***
enginesound=car1
throttlesound=car1
startsound=car1
hornsound=car1
acceleration=13
deceleration=40
topspeed=17000
idlefreq=22050
topfreq=55000
shiftfreq=26000
numberofgears=5
steering=160
steeringfactor=60
haswipers=1
*** end vehicle file ***

Warning : spaces and capitle letters are important in this file, so the easiest and safest way to create a car is to start from an existing file.

I'll go over each variable :

1. The first variable is "enginesound". It describes the standard engine sound. The value of this variable can be any wave file you place in the vehicles
folder. If you want to use e.g. the file "engine.wav" as a loopsound for the engine, this line will read:
enginesound=engine.wav
Make sure your sound sounds good in a loop to get the best result. The soundfile must be a mono sound and preferably 22050 Hz.
If you want to use a sound included in the game, the possible values are :
car1, car2, car3, car4, cycle1, cycle2

2. The next variable is "throttlesound". This is a sound that is used when the user presses the throttle to give the engine sound that extra punch. It must
also be a looping sound. In the game only the Firefow racecar has this sound defined. So if you want to use an ingame sound you can set it to :
car2

3. The variable "startsound" describes the sound for starting your car. If you want to use an ingame sound, you can set it to one of the following :
car1, car2, car3, car4, cycle1, cycle2

4. The variable "hornsound" describes the sound that's used for the car's horn. It must be a looping sound. If you want to use a sound from an ingame car,
use one of the following values :
car1, car2, car3, car4, cycle1, cycle2

5. The variable "acceleration" describes how fast the car can accelerate.

6. The variable "deceleration" decribes how well the brakes of your car work.

7. The variable "topspeed" describes the maximum speed of your vehicle. To give you an idea, the topspeed of the blackbird is 17000. To topspeed of the
Quattro is 26000.

8. The next three variables are used to play the engine sounds correctly, play with the values until your car sounds right :
- idlefreq : the frequency at which the enginesound plays when car idles, probably the equal to the bitrate of your file
- topfreq : the frequency at which the enginesound is played when the car reaches topspeed. Should be higher then the idlefreq. A good starting point is
double the value of the idle frequency
- shiftfreq : should be in between the idle frequency and the top frequency. This is the frequency the engine begins after a gear switch.

9. The variable "numberofgears" describes the... well... the number of gears.

10. The variable "steering" describes how well the car steers.

11. The variable "steeringfactor" describes how much the steering capability diminishes when speed increases, or to put it simple : how well you car behaves
at high speeds. This is put in percentages so it should be a value between 1 and 100. A value of 100 indicates the car steers just as well at topspeed
as when going slow.

12. The variable "haswipers" says whether or not your car has got windshieldwipers to use when it rains. A value of "1" says it does have wipers, a value
of "0" says it doesn't.
Just like with the track, you need the create a .wav file containing a sound describing your car that will be used in the game menu. It has to be named
exactly like the .vhc file.

That's it. You can leave variables out of the file and the game will use defaults.

Have fun!

This section describes how to build your own tracks for use with Top Speed 2. All you need is notepad and a microphone to record the soundfile describing
your track in the menu.
You need to create a textfile with the extension .trk.
Look to the zandvoort track for an example.
The file contains triplets of numbers. Each triplet describes part of the track. A triplet consists of :
1. The type of trackpart :
        straight        = 0,
        shallowLeft     = 1,
        left            = 2,
        strongLeft      = 3,
        hairpinLeft     = 4,
        shallowRight    = 5,
        right           = 6,
        strongRight     = 7,
        hairpinRight    = 8,
        straightCrowd   = 9,
        straightOcean   = 10,
        straightRunway  = 11

2. The surfacetype :
        asphalt         = 0,
        gravel          = 1,
        water           = 2

3. The length of that perticular part of the track, the minimum length is
5000. The number doesn't have a unit, but you could say that it is more or
less in centimeter.

The end of the track is indicated with a "-1" and the file ends with an optional 0 or
1 indicating weather :
        sunny           = 0,
        rain            = 1
The filename needs to end on ".trk" and needs to be placed in the "Tracks" folder of the game. Next you need a wave file with the same name as the track
containing the sound to be played in the menu. So if your trackfile is called mytrack.trk, you alse need to have a mytrack.wav in the Tracks folder.
If the filename starts with "adv" it indicates a streetadventure (although it will still appear in the "single race" and "time trial" menu). This means
the tracks are much narrower and there is only one lap.
end info.
I hope that helps