When this correspondent typed "Boxter", the helpful spell checker underlined it as a possible error. Apparently Porsche and its advertising agency can't afford such advanced software – but they can afford to spend a fortune on a huge billboard campaign for the misspelled Boxster.

This has caused great hilarity in the car industry. Porsche is famous for being the car company that guards its brands and trademarks more aggressively than anyone else – any third party that uses a Porsche logo or brand name without permission will get a warning letter before the ink is dry. Even publishers of classified ads have been forbidden from using any Porsche logos or branding when advertising Porsche cars for sale. Hence you often see a list of all other manufacturer logos, but simply the word "Porsche" in plain text with no logo.

How the poster for the "Boxter" managed to pass by the myriad approvals that every advert requires before publication is a complete mystery. To make it more ironic, the headline of the advert reads, "For some things in life there will never be an App". On planet Porsche that absence clearly extends to Apps that check spelling.

Our thanks to a quick-witted reader of the US website, Jalopnik, for spotting this one. We doubt the adverts will be up for much longer, but 10 points to anyone who sees one before it is covered over.