in my opinion rat look should be left to the aircooled lot. and i think if more modern cars are made to 'look' rat look, they often look like they are trying to be rat look. its a hard thing to pull of and get right. at the end of the day if you want to spend effort getting your car looking a certain way i can't see the point in wasting all that time to make it look crap.
i also think alot of people go rat look as its an easy way to give you car a 'style' when all you have to do is a bit of bothced painting and throw a load of crap at it....