Our cats have not tried to get under the dash, and we haven't blocked it in any way. I don't think it's a good idea as there are wires that could tangle them up. Cats do like to check every new nook and cranny. I hope she will be satisfied to have looked at it once.
If your cat likes to go into small spaces, be extra careful about bringing your slide in or out as you don't want kitty to get caught in it. We always check to make sure our cat is either in her carrier or visible in a safe place before moving the slides.