Originally posted by Astatu:

Yeah, I wish there was more I could do for it, but vehicle scripting is very obtuse and undocumented as it is. What you see here is cobbled together from the small article on the Source Developer Wiki, recycled HL2 vehicle scripts, and blind experimentation. It's a right pain.

Well, I've played with car's script, and it became better.
Here the part of script, that I have changed:

{
"wheelsperaxle" "2"
"body"
{
"countertorquefactor" "1"
"massCenterOverride" "0 -0.01 0"
"massoverride" "800" // kg
"addgravity" "0.33"
}
"engine"
{
"horsepower" "350"
"maxrpm" "3000"
"maxspeed" "45" // mph
"maxReverseSpeed" "20" // mph
"autobrakeSpeedGain" "1.1" // 10% speed gain while coasting, put on the brakes after that
"autobrakeSpeedFactor" "3.0" // Brake is this times the speed gain
"autotransmission" "1"
"axleratio" "4.56"
"gear" "1.86" // 1st gear
"gear" "1.59" // 2nd gear
"gear" "1.17" // 3rd gear
"gear" "1.0" // 4th gear
"gear" "0.84" // 5th gear
"shiftuprpm" "1500"
"shiftdownrpm" "300"

"boost"
{
// "force" "1.5" // 1.5 car body mass * gravity * inches / second ^ 2
"duration" "0.0" // 1 second of boost
"delay" "15" // 15 seconds before you can use it again
"torqueboost" "1" // enable "sprint" mode of vehicle, not force type booster
"maxspeed" "50" // maximum turbo speed
}
}
"steering"
{
"degreesSlow" "50" // steering cone at zero to slow speed
"degreesFast" "30" // steering cone at fast speed to max speed
"degreesBoost" "11" // steering cone at max boost speed (blend toward this after max speed)
"steeringExponent" "1.4" // steering function is linear, then raised to this power to be slower at the beginning of the curve, faster at the end
"slowcarspeed" "14"
"fastcarspeed" "20"
"slowSteeringRate" "4.0"
"fastSteeringRate" "2.0"
"steeringRestRateSlow" "4.0"
"steeringRestRateFast" "2.0"
"turnThrottleReduceSlow" "0.01"
"turnThrottleReduceFast" "2.0"
"brakeSteeringRateFactor" "6"
"throttleSteeringRestRateFactor" "2"
"boostSteeringRestRateFactor" "1.7"
"boostSteeringRateFactor" "1.7"

"powerSlideAccel" "250"

"skidallowed" "1"
"dustcloud" "1"
}