robbie wrote:why do you need mudflaps?
I have heard a few people say they needed mudflaps for 4bies, I know you dont need them on passenger cars
Extract from ADR 42/03. MA = passenger car (4x2). L-Group = motor bike. If you have a ute read 15.2
15 WHEEL GUARDS (MUDGUARDS)
15.1 Wheel Guards for Passenger Cars (MA) Vehicles Only
15.1.1 General Requirements
The vehicle must be provided with wheel guards (parts of the bodywork, mudguards, etc) which must be so designed as to protect other road users, as far as practicable, against thrown-up stones, mud, ice, snow and water and to reduce for those users the dangers due to contact with the moving wheels.
15.1.2 Special Requirements
15.1.2.1 The wheel guards must meet the following requirements when the wheels are in the straight ahead position:
15.1.2.1.1 in the part formed by radial planes at an angle of 30 degrees to the front and 50 degrees to the rear of the centre of the wheel (see Figure 1), the overall width (q) of the wheel guards must be at least sufficient to cover the tyre ‘Section Width’ (b) of the tyres fitted to the vehicle taking into account the extremes of tyre/wheel combination as specified by the ‘Manufacturer’;
15.1.2.1.2 the rear of the wheel guards must not terminate above a horizontal plane 150 mm above the axis of rotation of the wheels (as measured at the wheel centres) and furthermore the intersection of the edge of the wheel guard with this plane (point A, Figure 1) must lie outside the median longitudinal plane of the tyre;
15.1.2.1.3 the contour and location of the wheel guards must be such that they are as close to the tyre as possible; and in particular within the part formed by the radial planes referred to in clause 15.1.2.1, they must satisfy the following requirements:
15.1.2.1.3.1 the projection - situated in the vertical plane of the tyre axis - of the depth (p) of the outer edge of the wheel guards, measured in the vertical longitudinal plane passing through the centre of the tyre, must be at least 30 mm. This depth (p) may be reduced progressively to zero at the radial planes specified in clause 15.1.2.1.1;
and
15.1.2.1.3.2 the distance (c) between the lower edges of the wheel guards and the axis passing through the centre of the wheels must not exceed 2r, ‘r’ being the ‘Static Loaded Tyre Radius’ of the tyre;
15.1.2.1.4 in the case of vehicles having adjustable suspension height, the above mentioned requirements must be met when the vehicle is in the normal running position specified by the ‘Manufacturer’;
15.1.2.1.5 the wheel guards may consist of several components, provided that no gaps exist between or within the individual parts when assembled; and
15.1.2.1.6 the wheel guards must be securely attached. However they may be detachable either as a unit or in parts.
15.2 Wheel Guards for Vehicles other than MA and L-group Vehicles
15.2.1 General Requirements
All wheels of a motor vehicle or trailer (including a ‘Prime Mover’ capable of operating without a ‘Semi-trailer’) must be provided with wheel guards which must be so designed as to protect other road users, as far as practicable, against thrown-up stones, mud, ice, snow and water and to reduce for those users the dangers due to contact with the moving wheels.
15.2.2 Special Requirements
The wheel guards on the rearmost wheels on vehicles other than MA and L-Group vehicles must provide continuous protection between a point in area A and a point in area B in Figure 2, and must be provided for the ‘Overall Tyre Width’ of all tyres.
15.2.2.1 In the case of steerable wheels, the requirements of clause 15.2.2 must only apply when the wheels are in the straight-ahead position.
15.2.3 Wheel guards may consist of either permanent body structure or part structure and other components, including mudflaps, provided the specified protection is retained during vehicle operation.
15.2.4 Where 2 or more ‘Axles’ form an ‘Axle Group’, separate wheel guards may be provided for each rear wheel or a single wheel guard may be provided which provides continuous protection from area ‘A’ of the foremost wheel to area ‘B’ of the rearmost wheel in Figure 2.
15.2.5 Notwithstanding the requirements specified above the wheel guard including a mudflap (if fitted) need not be less than 230 mm from the ground for other than off-road vehicles, or 300 mm in the case of vehicles designed for off-road operation.
15.2.6 The requirements of this part does not apply to any vehicle the construction or use of which is such that, in the opinion of the ‘Administrator’ it is unnecessary or impracticable to provide a wheel guard(s).
15.3 Wheel Guards for L-Group Vehicles
15.3.1 Wheel guards may consist of either permanent body structure or part structure and other components, including mudflaps, provided the specified protection is retained during vehicle operation.
15.3.2 General Requirements
The wheels of a vehicle and the wheel of a side-car must be fitted with wheel guards of width not less than the ‘Section Width’ of the tyre. The wheel guards must be so designed as to protect other road users, as far as practicable, against thrown-up stones, mud, ice, snow and water and to reduce for those users the dangers due to contact with the moving wheels.
15.3.3 Special Requirements
15.3.3.1 Rear ‘Axle’ and Side-car
The wheel guard provided for the rear wheel and for the wheel of any side-car must extend not less than from a point vertically above the foremost part of the wheel rearward to a point not higher than the intersection of the arc of the wheel guard with a line through the centre of the wheel at 45 degrees to a horizontal plane through the centre of the wheel when a mass of 45 kg is distributed in the saddle of the vehicle at its ‘Unladen Mass’.
15.3.3.2 Front ‘Axle’
Where a wheel guard(s) is provided for the front ‘Axle’, it must extend not less than from a point vertically above the centre of the wheel rearward to a point not higher than the centre of the wheel or to the point where suitable protection is afforded by the frame or other construction of the vehicle when a mass of 45 kg is distributed in the saddle of the vehicle at its ‘Unladen Mass’.
15.4 Visibility of Wheel Guards (Certain Vehicles)
Except when ‘Rear Marking Plates’ are fitted, for every rear wheel guard affixed to a motor vehicle, or trailer which is 2.2 m or more in ‘Overall Width’ and which has a body of the tray type, that portion of the external surface of such wheel guard which is visible to the rear of such vehicle must be white or silver in colour and clearly visible.
HYPOFAB 
