Possibly because of the sheer number of trailer queens that turn up. I've never seen as many anywhere else.
And the amount of mirrors on the floor... if someone's really that interested in looking at sills that have never seen drizzle let alone been plastered with rainy road grime, they'll get on the floor and look underneath...
IMHO if all you do is polish it and drive it in and out of a covered trailer, you might as well just get one from Corgi...
(you may have guessed I'm not a fan of OCD Concours

)