Due to different cup sizes , is there anything that can be inserted to cup holders so that there is a spring-loaded catch to hold the cups in place? It's really annoying to hear the rattling noise due to free play of the cups when they are not the exact size of the cup holder. Something like that works for our 3IS.

 

Maybe something like this:


or this:


It looks like it has rubber pads on the sides so the cups wont rattle..

 

Yes, something like that... gonnna measure to see whether it fits.... thanks!