Realistic steering

So I’ve seen plenty of contraption with realistic steering; just a wheel, suspended by 2 or 4 ropes,and nothing else. these wheels turn like actual car wheels do,and also steer like any car would do.

A good example can be seen here:
http://www.wiremod.com/forum/finished-contraptions/29817-dune-buggy.html

No constraints at all,just a linked ACF gearbox w/ engine.

So exactly how can someone make this?(even without ACF) wouldn’t the constraints make the wheel stay in place rather than spin? and what about steering? i’ve seen some cars that use a beam of metal/wood,and the wheels follow the turning motion of that beam.
It’s hard to explain,but i hope you get what i mean.

Is there a tool that does this? if so,what tool?

Thanks in advance.