maccayak and
Burnsy
Mrs XF says to tell the girls that their worries are misplaced. Maybe revisit the "What do you put on the floor?" thread?
We spend SIX WEEKS (semi) free camping on a sandy site at the beach every summer. Our carpet decision arose from that experience and that was decades and three vans ago! Nothing worse IMHO than gritty sand underfoot (bare feet) on vinyl flooring. Or when it's really hot the sandy, gritty, sticky feeling. A small stiff brush and dustpan or 12v auto vacuum cleaner for DAILY cleaning takes no longer than sweeping the vinyl. The thermal/sound insulation effect works all year round.
If you see my earlier posts you'll also note that we always select light coloured pile carpet as well (as we do at home) It's brighter and maintains the feel of space in the 18.57-7. Looks cleaner for longer than darker colours, pile holds sand and grit away from feet. Rare dirty marks addressed with Vanish Preen powerpowder large area carpet cleaner.
We get the seconds or off cuts from house lots at a big carpet distributor. Good quality at heavy discount. Current lot (2 pcs) $80 with enough leftover to make some mats.
Even the rusted on cynics have to admit it's a good idea once they actually visit and see it in action.