Car art, or not?

Consider the Jeepnies, the Mass Transit of the Philippines. The folk-art Jeepnies started out as old WWII Jeeps and have been around for over 60 years. No two are the same, all have names given to them by the owners/drivers, and are a source of pride by their owners and passengers.

The question I'm asking car nuts (not "artists, "but "car nuts") out there is, when is it okay to modify what by many are considered classic designs and when is it not okay?
Does applying what many may consider to be an outrageous paint job, or bizarre decoration on a revered sports car or cultural icon teeter on, if not cross the edge, of being sacrilegious?
Does it really matter, as only the owner needs to be happy with the results?

© Source: original article on Straightline