"Cheap cars. Be quick. They won't last."
Not sure it was as English error actually.
Here are a few other examples of bad sentence structure:
outside a secondhand shop:
we exchange anything - bicycles, whashing machines, etc.
why not bring your wife along and get a wonderful bargain?
sign in a laundromat:
automatic washing machines
please remove all your clothes when the light goes out
spotted in a toilet in a London block:
toilet out of order. please use floor below.
And finally, something that ties in more to the theme of this thread:
sign on a repair shop door:
we can repair anything.
(please knock hard on the door - the bell doesn't work)