Just ordered SR+, Aero, Black interior today (3/11). Instead of modifying my original reservation, which I made on 3/31/16, I accidentally ordered separately, thus creating a second reservation number. I called customer service rep and they said that this isn't a problem, just cancel my original reservation and I'll get a check for the $1k back. Duh. Anyways, the rep also said that canceling the original reservation and creating a new one will have no impact on when I would receive my car (as opposed to having simply updated my existing reservation number with the order). Not surprising I suppose.