If you are currently on a trip, and having so much fun you don't want it to end, you have the option to extend the rental. Contact the owner at least 12 hours before the rental is scheduled to end to make sure the RV is available for extra days. If they agree to the additional dates, you will need to suggest a change to the terms of your rental. Any extra days must be officially booked through the site or you will not have insurance coverage or roadside assistance.
Once you have suggested a change, the other party must accept the new terms, to put it into effect. When they have accepted, the change is automatically charged and updated in the details. If the new suggestion is not accepted, the rental will move forward under the most recent terms.