The biggest reason to not attempt early registration is that if you were to get it wrong, you can get late registration fees 45 days after the date on the MCO (the reason the kit doesn't come with the MCO to begin with). Not to characterize Mr. Mayor's words but he and I and everyone else I've talked to are convinced he slipped through the cracks without the SC Form 4038. That's the one a DMV agent has to sign, but they're only checking that the serial number on the MCO matches the tag on the chassis and your paperwork. I will give you his number (privately) if and when you want it. They may be able to confirm they won't sign off if the car isn't built. They also recommended I send in pictures of my car completed with all of my paperwork, so that would be discouraging unless you wanted to make an attempt anyway.
My summary from May 7:
- Get insurance
- Pay property taxes on MCO/invoice
- Get DMV agent signature on Form 4038
- Complete Form 400
- Complete MV96 (if you want a personalized plate)
- Send in the forms, checks, MCO, invoice, pictures of the car, and copies of insurance and paid property tax receipt
Full disclaimer though, they haven't cashed my checks yet or called me or anything like that.