Embasy cars and some official cars have the authority to use "jalli number plates" for security reasons, Since any one can track owners and addresses its not safe for them to use a particular car plate. The SUV is probably registered but is being driven on a jalli plate.
Ive often seen Toyota Hi-ace coming out of the Saudi consulate with a Private cars registration plates, Where as it should have a commercial or a private van registration series.
But yes in this case the car can be a NCP or God knows maybe the SUV is a stolen SUV,
PS: Its documented that a stolen Landcruiser was once recovered from Bilal House, Karachi