Omvic covers cancelling an agreement for regular sales but not specifically for Factory orders.
"Please review the entire contract, including all attached statements, before signing. This contract is final and binding once you have signed it unless the motor vehicle dealer has failed to comply with certain legal obligations. "
You didn't give a deposit but did provide a credit card so they might have hit that for a secured hold of the deposit amount, I'd check with your credit card company first. If they didn't, then go in and tell them you can no longer wait and see what they can do. I'm sure they don't want the bad press so I'd gently suggest that you have a following online and you'd be happy to tell everyone how wonderful they have been. I would probably not tell them that you intend to purchase elsewhere, just that you've decided to wait until there are more options, the carnival has proved itself, the newer AWD or Hybrids are available, what ever makes it work.
Good luck. Remember, leave the emotion at the door, if you start demanding things or yelling and screaming they probably won't work with you.
In the immortal words of Patrick Swazye in Road House "Be Nice"

(lol)