The GT is OBDII compliant
The below is a directive which will close this issue and allow you buy the OBDII and scanner without a problem.
2004 or newer model year diesel vehicle sold in the European Union
Commission Directive 70/220/EEC, Annex I:
8.2. Vehicles with compression-ignition engines
Vehicles of category M1, except
- vehicles designed to carry more than six occupants including the driver,
- vehicles whose maximum mass exceeds 2500 kg,
from 1 January 2003 for new types and from 1 January 2004 for all types, must be fitted with an on-board diagnostic (OBD) system for emission control in accordance with Annex XI.
However, this still does not answer the question as I ask myself this question:
My car has the 16-pin OBD connector, shouldn't it be OBD-II compliant?
No, not necessarily. A lot of European and Asian manufacturers equipped their vehicles with D-shaped 16-pin connectors long before they began installing OBD-II systems on those vehicles. One curious thing to note here is the fact that most non-EOBD compliant vehicles had a DLC that does not fully conform to SAE J1979. I suggest you do 3 three things before you buy one.
1, speak with your dealer - i dont thin you will get very far as they will know less than you. they just know how to sell and put basic parts together like lego.
2, open the connector and check if the shape of the connector. the ODBII will have it shaped like ears. trust me! the EOBD compliant ones will not. it will be shaped like a D flat ways.
3, if your still not happy check under the bonnet and look for the vehicle emmissions control sticker and in the corner (right hand side of sticker) it will state if its OBD II certified.
The 3 options above will confirm if you car is complaint or not.
I hope this puts it to bed.