[Meta]

You've to script it all, but it's not easy.
Use this functions:
https://sampwiki.blast.hk/wiki/SetVehicleVelocity
https://sampwiki.blast.hk/wiki/GetVehicleVelocity

If you want to make a really good system, you recieve a lagparty, too...

EDIT: or use https://sampforum.blast.hk/showthread.php?tid=179089 :P