When we did dog shows, I cut thin carpet to fit the living area with the slide in and another strip to add when the slide was out. I used contact cement, (water based) to glue vinyl carpet runner (with the medium spikes) to the carpet. Kept the carpet in place and somewhat spill proof. Also when the big piece was cutout and fastened under the floor registers, it really stayed put.
On the other hand, Lowes and Home Depot have carpet runner (rugs) in rolls with non skid backing.
Hooligan, Pensacola, Fl -U.S. Coast Guard 1956-1985
2016 Thor Siesta Sprinter 24ST diesel -1972 Moto Guzzi
2008 Suzuki Grand Vitara TOAD