But if I have a chance to use the digital one, why does it have to be wrong?

It doesn't have to be wrong necessarily, that's right. But LFS is still in the Alpha-Stage and some (a lot) of the interiors aren't finished yet (at least I hope so). So for the finished S2 you have a good chance to get your digital speedo in a good looking way, until that you'll just have to bear with its looks