If you email Alfa Romeo UK with the registration number and chassis number they can tell you if its a Prodrive or not, they cannot issue replacement certificates anymore though. At the end of the limited Prodrive campaign there were bits left over so there are cars out there with 'some' Prodrive bits on. You can buy an 'S' badge on ebay so dont put too much value on that. The seats to, after mid 2008 all 939 Spiders and Breras had the later seats, however the Prodrive seats had a different insert. But these things are superficial. The main thing is the uprated suspension and wheels all which knock about 100kg off the weight of a Prodrive. The car in question looks like a regular Brera with some bits on, in which cas nearly £10K is not cheap.
The Brera in question is not a Prodrive, It a Brera S,
as for there were some bits left over, that is here say, nothing more, a bit like there were 500 Prodrive's built, Alfa and Prodrive went there own ways before the full 500 were built.
The Car in question should have the Prodrive suspension including the rollbars,
but as with most cars of this nature the experts get involved, so it is a possibility the suspension could have been changed, but when car was released as new it would have been with the Prodrive suspension kit, every thing else was an option that came at an extra cost.
As for contacting Alfa UK you do not need the chassis number,
And what you will get back is this below, if the car was released by Alfa UK as a Brera S