As per the title, will the standard rubber top mounts found on the STi suspension fit coilovers (D2/KSport type shocks)?

The reason I am asking is because I am thinking the standard rubber top mounts will reduce some of the harshness associated with using aluminium/steel pillow ball and standard top mounts.

Best to ask an agent on the specific suspension you're looking at, both KW and Whiteline coilovers fit the OE topmounts, Motons don't at present.