Binding this to W key would work.
_dir = getdir vehicle player;
_pos = getPos vehicle player;
_pos = [(_pos select 0)+2*sin(_dir),(_pos select 1)+2*cos(_dir)];
vehicle player setpos _pos;
there you go.
So like //W key:
{
_dir = getdir vehicle player;
_pos = getPos vehicle player;
_pos = [(_pos select 0)+2*sin(_dir),(_pos select 1)+2*cos(_dir)];
vehicle player setpos _pos;