If you are saying civilian suv together with other police
vehicles, then the civilian suv is a unmark vehicle. How do you
make a different? The car plate number remains the normal one ,
e.g. SFTxxxx, but you can notice the IU unit which is the same
colour as police vehicle (sort of green). Which are the vehicles
using as unmark cars? They can be Ministers' and their bodyguards
cars, including PM, SM and MM. If I'm not wrong, they includes
Volvo and Land Rover.
They are to escort VIPs and Minister and most of the time, there
should be at least 2 traffic police on bike to stop traffic and to
lead the team.
Only for President, then the police will secure the whole stretch
of road with police from the individual Police Division. For
others, the police will not be securing the road.