There are many devices to protect the towed I will address.
Some motor homes come with a full width mud flap, Or a Brush type full width mud flap.
Hoover makes a vacuum that "Beats as it Sweeps as it Cleans" the beater bar is supposed to make dirt jump up out of the carpet, as are the brushes and those full width mud flaps and brushes..... Do precisely the same thing
There is a plastic shield that mounts on the tow bar, Some folks swear by it.
I used (And will again when I finally install it) a "RV underskirt" now I understand it's sold under a different name now, But I'll describe it
It is a heavy Mesh fabric thing that stretches between the RV and the Towed, dirt and debris kicked up by the RV hits it and bounces back down So the "Shiny side" stays shiny and the dirty side dirtier, but that under the car.
it works well.. I can not testify as to the plastic rock guards for I've never used one.. But others seem to like 'em.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times