£2K is the maximum discount on the Ford Privilege scheme, used to be a flat percentage but it changed some years back.Whether this will change in the future is anybody's guess. It was the same when the mk2 RS came out. There was hardly any discount applied via privilege (If any) through the time it was on sale. From what people have said it was a maximum of £2,000 off. Which is a bit of a difference when you look at some members getting 7k+ off a ST with privilege.
When I was looking at the mk2 RS it was on the privilege scheme and you got the full £2K off the price. However that was the limit to any deals they were doing whereas with the ST there were also dealer discounts applied on top of the privilege saving. These weren't specific to privilege customers as far as I understood it.