Motorhomes are not fun to clean IMO. They are very cramped (see can’t even use full sized buffer sometimes) and the carpet and upholstery are usually VERY dirty (no walk off area from outdoors to indoors, so you’re basically cleaning a huge entry mat). I try to avoid them, but if you are going to clean one, be prepared to give yourself a lot of time, and charge accordingly (similar to what Gordon said but aim for $100/hr min). Also, unfortunately be prepared to do a lot of extraction work, and make sure you have power accessible (seems like common sense, but something customer doesn’t always take into account when scheduling the job based on where motorhome is parked).