There have been a handful of times over the the past several years where customers have inadvertently stepped on the folded down cup holder... damaging or breaking a part.  If the clear mounting plate is undamaged, you can order a replacement part for $10 including shipping.

If, by chance, the clear backing plate has been damaged/cracked somehow, you may purchase a new clear backing plate that has been drilled and tapped to accept the black/fold down cup holder you remove from your damaged backing plate... reusing the same 4 screws.  The clear backing plate may be ordered for $24 including shipping.