I saw the videos on the Senna F1 kit and they send you a parts pack every month through out the subscription. These kits are more of an assembly of pre - finished parts. There do not seem to be many parts that require painting or the application of decals. That being stated, I would be extremely concerned about making a catastrophic mistake and sending $2500.00 down the drain.
If you have an Ace Hardware close to you, they have a color that I believe is called School Bus Yellow, which is virtually the same as the GM color. I have painted a couple of Kodak cars using the MCW paint, which is supposed to be the GM color. The School Bus Yellow is virtually the same.
I have read most of this thread and will say this. This technology is coming and it will do amazing things. Whether a model kit is one of them, time will tell.
The only problem I see with this idea is that it transfers all of the risk to the buyer. Right now if two of us buy a kit, we both get the same thing and the quality is the same. With 3D printing, the quality of the model may come down to who has the best printer and possibly the supplies. Given the printers out there for printing of text and graphics, a person can spend $30 up to thousands. The print quality is different as is the capabilities. If one is printing a school report, it largely does not matter what kind of printer the person uses. If the person is doing high end work, the printer matters.
If this is where we go with 3D printed models, the concept may be in trouble. If I can only afford a low end printer and the printed model is low end, there is no point. I may be able to turn it into something nice, but if I am in a contest with a person of the same skill set who has the high end equipment the result will likely be very different. It would be like taking a person who built a kit box stock and put him in the same class as one who machines his own kit.
As I stated at the beginning of this post, the technology is coming and it will do amazing things. We will have to see how or if it applies to model kits.
If I may offer a suggestion, the only thing you can do is make the builders prove they built the model. Make them bring the box, the instructions, etc. The judges are a different matter. You can have bad judges no matter how hard you screen them.