Walla2, that looks like a good solution for me (I've got black perf interior with red piping and CF accents). Does the string come with the holder? In the pictures on Amazon it doesn't show the string attaching the key to the holder. Amazon is out of stock on the op tech mini loops, so I'm looking for a solution until they're back in stock.
The leather holder comes with the metal clip and a leather loop that goes into openable screw rivet. The op-tech mini loops (the string) are separate/not included. I put my op-tech mini into the rivet and then push it in-line with the rivet to make everything as compact as possible.