I have seen a Zetec S/ St style rear spoiler on eBay in black but it is advertised as only fitting 12/13 Focus models only? Is this a mistake on their part and would it not fit say a 2015 Focus? It's not a genuine Ford part so could this be an issue also? Would I be better off buying the Spoiler from a Ford dealership?

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its not better get second hand one genuine ford from ebay ?

 

for me look like will fit

I have been looking for a while but haven't come across a genuine second hand one yet on eBay. All seem to be knock offs. Woulde prefer genuine parts all right. I don't know wether to chance it and buy it or wait for genuine Ford one to be advertised.

It does look like it should fit though. 

are you ok with respray ? or want black

https://www.ebay.co.uk/itm/Genuine-Ford-Focus-Mk3-ST-Spoiler-Stealth-Grey/123163408478?hash=item1cad1c785e%3Ag%3ACr4AAOSwT2pbRR70&_sacat=0&_nkw=focus+st+spoiler&_from=R40&rt=nc&_trksid=p2060353.m570.l1313.TR11.TRC1.A0.H0.Xfocus+st+spoiler.TRS0

I would prefer a black spoiler to be honest. Save me the bother of having it resprayed. Thanks for the info though. 

I have bought the black spoiler and it looks like it will fit. Just wondering will my existing brake light fit it or will I have to get a Zetec S / St line brake light for it?

Your existing light will fit,  but I don't know about the length of the lights wiring as the st/zetec-s spoilers are more prominent. I think the brake lights for the st/zetec-s are white lens not red, the water hose pipe will need a extended piece of hose to reach the jet..

Thanks for that. Luckly the spoiler has come with an extension for the hose pipe. 

Finally got the the ST rear spoiler fitted. It looks class!