I think most people say that an Oil Cooler isnt needed on a RS (correct me if i'm wrong peeps!).

That one on ebay isnt water cooled, it just has the oil pumped through it and radiates the heat to atmosphere, just like your normal rad does with your water, and your intercooler does with your charge air.

If your looking for a water cooled oil cooler then that is not the one! lol