Trademarks are valuable because they are for consumers to know of and about a business’ brand, products or services. So trademarks should be used in a manner that relates to and is visible to the customers. If your customers might encounter your trademark in their rear-view mirror, it makes perfect sense to display your trademark backwards.
See my client’s slogan – If You Can’t, We Can! – below used backwards on the front of a work vehicle, a perfect example for Michael and Son, which has dozens of vans and trucks out on the roads everyday!