And those covers have the real glove compartment ( literally ). So buy a set of mechanics gloves and put them in there. Not sure but I think the OE was a set of white gloves .
Years before I had the SC installed in my 94 ( that years 968s no longer had the covers ) I bought a cover and had it secured in place by two small rubber pucks , I bought at a hardware store, one on each side mounted against the frame . And yes, the cover will stay in place without anything at all, but itll have a little play, unless you use something to keep it pressed in.
Nice, complete engine bay look , IMO.