An illegal b/bar on a car is any that are upright or have a forward slope (as pictured) i.e the bar must have a rearward slope.
On a 4wd or truck the bar can be upright but must not have any forward sloping component.
The bar cannot have any protrusion forward of the barwork, i.e. aerial mounting brackets, winch gear or fishing pole holders. These are what Police would be looking for.
For RWC there would also be issues of air bag compatibility, manufacture date of the vehicle and compliance measurements.

