totally disagree about your point about the only differences...the construction of the body is one of the the most significant differentiators. Bonded aluminium bodies, no joints etc etc. Saw on one of the several motorhome programs on the box earlier this year a walk around one of the largest UK motorhome manufacturers factory - basically a timber stud work timber frame stuffed with insulation and clad in aluminium panels.As an aside on this point, the design or cars and motorhomes really isn't that dissimilar. Most large motoring consortiums will design a common "platform"/chassis that will then be used across multiple brands and models. Really the only difference you are paying for between those models is the badge on the front and some upholstery and minor styling differences.