It will depend on the year your car was built. If it's a 2015 or 2016 then it *could* have had the GTS parts fitted from the factory. The GTS was launched in 2014 and a little while afterwards the bodykit was released to other cars as the SportDesign package. It's a rare option though, not many people seem to have specced it. It was also available, and still is, as a Tequipment dealer fit option at £2849.
I think an OPC may be able to check on their system, using your VIN number, if if was factory fitted. If not, then assume it was a later OPC fit and the paperwork has been lost. It may still show up in the system if it was OPC fitted? I'm not sure how connected all the dealership work orders are.
If your car is a 2015 or 2016 build, I would say it's most likely it was factory fitted as the SportDesign option.
I think an OPC may be able to check on their system, using your VIN number, if if was factory fitted. If not, then assume it was a later OPC fit and the paperwork has been lost. It may still show up in the system if it was OPC fitted? I'm not sure how connected all the dealership work orders are.
If your car is a 2015 or 2016 build, I would say it's most likely it was factory fitted as the SportDesign option.