Graphically, I love the card the way it is. I think it's perfect, honestly.
that being said, I don't think I'm using them right... when I see a business card on my vehicle, I immediately think someone is trying to sell me something and chunk the card, especially if I have no context. I've passed out probably close to 45 cards in the last two months and have only had a handful of people actually come to the board.
so, I'm starting to write things on the back like "you're got a sweet ride. some checkout our online Jeep community, we'd love to have you." or stuff like that. Do you want to print something on the back of the card that is a little more descriptive as to what we are and why they got the card, or do you still want to have the "cool mystique" of a random card with a website and you get to "discover" what it is all about... I'm fine either way, but if the cards are one of our main marketing devices, then they could be more effective, either through execution (writing stuff on the back, leaving a note, etc...), or through design (modifying the card to convey more information). If we put more stuff on the front, though, I think it looses it's cool. I love the design. The fish jumps out at some people, doesn't at others, but in my book, it's the best card I've ever seen...
my 2 cents.