ok, without giving you the answer it's best to think of it in these terms:
you need a few variables
1. the car
2. the amount of thrust when key is pressed
3. the cars velocity
4. the friction coefficient that will slow the car down
Friction = .99
if key is down then thrust = 0.01
car_velocity = car_velocity + thrust
car_velocity = car_velocity * friction
add the car velocity to the car position
in b3d you can just rotateentity and moventity. the sin/cos is done for you
you need a few variables
1. the car
2. the amount of thrust when key is pressed
3. the cars velocity
4. the friction coefficient that will slow the car down
Friction = .99
if key is down then thrust = 0.01
car_velocity = car_velocity + thrust
car_velocity = car_velocity * friction
add the car velocity to the car position
in b3d you can just rotateentity and moventity. the sin/cos is done for you