I definitely prefer one of these to the original green 'M':
They carry over the image on the website and, to my mind, that image is spot on. I feel the consistency of image is very important and should be distinct and different to all others, including WC. It is uncluttered, eye catching and would look good as a relatively large graphic on the rear of vehicles (!) or as a smaller graphic in the windscreen of vehicles (!).
The words are OK. On balance I prefer 'Living The Dream' over 'Happy Campers'.
Whatever you choose for this sticker it is likely to become the site's tagline (strapline) as is:
I'm Lovin' It (McDonalds)
Delivering Sustainable Distribution (Eddie Stobbart)
Every Little Helps (Tesco)
Just Do It (Nike)
I hope this helps. Would a site competition for the wording work for you, Phil?
Colin