just below the handbrake lever with an odd shaped cover which will need lifting up with a small screw driver (zafira A)
On the early "Vectra B" models it's under the trim immediately under the Hand-Brake lever.
OBD2
The OBD2 connection port is located underneath the right side of the glove box in the passenger side foot well. It's a bright green connector.
Yes the MK6 Transit is OBD2 and the port is jus down below the steering wheel
LOCATION OF OBD2 PORT?
The OBD connector is located under the center console on the passenger side. It is OBD-II although not fully compliant.
behind the ashtray, obd2.
The OBD2 connector is located underneath the ash tray.
Vauxhall frontera diagnostic OBD2 : Feel Under the Fuse Box: Drivers side:16 PIN.
The OBD2 plug is located under the drink holder under the center console.
Drivers side lower dashboard close to a pillar
It is located left of the engine under the turbo.