Mine are just like Phil's.Mine dont go all the way on but not as loose as your telling us..main problem I can see is either the top of the strut is touching the inside of the cap or the cap is touching the captive strut nut..
Bit of a measure ..distance from captive nut to top of strut and the distance inside the new cap..nothing a drill wont sort out..Mine are just like Phil's.
When I get a bit o spare time, I am going to have a good look at them to see if they can be modded to fit a bit better...
4) if it should never move again - use...just fitted a pair of FIAT 500 strut caps as recommended - they are secure but don't seat around the edge as well as I'd like, so I think I'll run a bead of silicone sealant around the mating surface...
...silicone sealant is the 3rd item every toolbox needs:
1) if it moves when it shouldn't - use duck tape
2) if it doesn't move, and it should - use WD40
3) if it doesn't seal properly - use silicone!
Top marks on this post..They should actually screw onto the bolt sticking up from the suspension strut - If you push them on, you will never get them to fit snugly. Mine have been on for 2.5 years now, and never moved once. I bought the Fiat 500 ones - perfect fit!
Wrap some tape around the 3 fingers on the underside to pull them in slightly tighter..then try screwing one on gently..I couldn't get them to fit tight either. Tried screwing and mine are Fiat 500. Perhaps the amount of exposed thread varies. I used large diameter O rings to fill the gap 62 mm X 3 mm.