Hi there,
Since I already tried to make my own boot clips from a sheet of plastic, dril a 25 mm hole in it and saw in half at two/thirth of this hole, i never had any problems. Only, sometimes you have to lift your C5 up, and the plastic snaps. Now, accidentally,(on a very old C5) I found this solution for the clips instead. Just buy a couple off these.
Drill a hole through the bootholders, (where you normally expect the clips to be.) and push this pen through, ready!
I'm probably not the first to mention this solution, but I find this a good solid and workable way to go!
greetz
Frank