Update :
I'm getting my Z registered next week (had a bunch of bills to pay this week). I talked to a local Z owner in DFW and he informed me that the DMV gave me the wrong information. I can get my car registered with the backfees waived because the car is over 25 years old. Sure enough, I called the DMV and they told me it was only going to be 130 something odd dollars to get it registered.