Are subframes OEM on 1999 Convertibles?

I have a 1999 3.8L V6 convertible "35th Anniversary" Mustang that I bought used in 2000 with 17,000 miles on it. Back in late January I got into an accident and my car wound up bouncing off of a guard rail on the drivers side. Here's my problem - I brought it to a local body shop who contracted the alignment out to a Midas. Well, the Midas guys called me up and said the alignment couldn't be done without customizing the car. The issue? Subframe supports on the bottom of the car. There are 2 that run parallel with the body on both sides and one large one underneath the engine. I did not put these on and I highly doubt that the previous owner did as that was a rental car company. The Midas refused to do the alignment and then the body shop owner contracted the job to a Monroe Muffler who also refused to do it. I got my car back on Monday and the alignment still isn't done. I can tell it's out of whack and I'm taking it to a Ford dealer on Friday to get the alignment done with the body shop footing the bill. Does anyone know if these subframes are OEM? I don't see how they wouldn't be as it's a convertible car and it would make sense to have them to keep down body flex.

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Paul