Most of these things are regulated already.
ROAD TRAFFIC (VILLAGE VEHICLES) REGULATIONS(3) No person shall without the written permission of the Commissioner drive
or use a village vehicle on a road if the load carried by the vehicle-
(a) overhangs the front, rear or sides of the vehicle; or
http://www.hklii.hk/hk/legis/en/ord/374/s12a.html(a) the issue by the Commissioner of permits for the driving and use of
village vehicles on roads;
(b) the construction and maintenance of village vehicles,
http://www.hklii.org/cgi-hklii/disp.pl/ ... N/s20.html(1) The Commissioner may at any time require the production for examination by a vehicle examiner of all village vehicles
So the laws exist; make a police report if you see an infraction.