[Motor31]

That's a continuing "gift" of the "feature" that DRV built in by cutting notches in the bottom slide seals. The tires are close to most of the notches and any dirt, dust or just plain crud they kick up is available for migration. You might want to make sure all windows, vents and the flapper on the microwave vent are locked down tight to stop air flow as much as possible. Then keep the broom handy in the kitchen.

Also be prepared for dirt transfer to the living room from dust and water that get caught on the bottom of the slide fabric. It gets transferred to the carpet when you pull the slide in. If you are in a wet area it will be especially noticeable when you open the slides the next time.