"Old wild west" secret sauce I don't know if the "Old Wild West" franchise even exists outside of Italy, but I'll give it a shot anyway.
In those restaurants they serve this sauce, 



which colors resembles much the one of a cocktail sauce. In the sauce there is something solid that I believe to be tiny pieces of chili peppers.
It has a neutral smell and tastes creamy, slightly spicy. It is very good to eat with sausages or roasted meat.

I have asked the waiters to tell me the recipe, but they wouldn't. Once, a friend of mine told me that it was a mix of mayo, ketchup, chili peppers and worchester sauce. I tried several times to mix them with verious percentages of the components and nothing I could come up with tasted anything like that.

Can you help me to understand the recipe?
I've never been to Old Wild West but that looks very much like "fry sauce" or "secret sauce" as we use them here in the United States. In looking at Old Wild West's website, it appears to be geared around offering traditional US style burgers, fries, steaks, ribs, etc. so the inclusion of US style fry sauce would make sense. Here is a link to a typical version that would be used here: http://www.epicurious.com/recipes/food/views/epicurious-not-so-secret-sauce-51261820