Ok, I figured out where I saw it... Feb '04 Excellence. Article near the back about tuning coilovers on a 911. Shows pics (page 146) of the slotted mount, NOT a hiem like I thought. Would be very easy to duplicate.
Sandeep, I'll try sending you a scan from the page. It shows specifically what you want to be able to do.
(I would post it, but I think that's a big copyright no-no
)