Before I get to the advice I want to say to Markus, Andreas and the rest of the development team from what I've seen in the screenshots of V13 this is going to be one killer of a game. I love what I've seen so far. I can't wait for April to get here!
Now to the advice. To those of you who do decide to pre-order, when you complete your purchase you might want to write down your Order Number(s) and your Serial Number(s) and keep it in a safe place where you know it is at or to those that use the Windows OS perhaps copy and paste them into a Notepad file on your desktop. I say this in hopes that when the game is released to those that pre-ordered, we in Customer Support aren't inundated with requests for us to look up your Serial Number.
I have mine written down and pasted into a Notepad file. Do you have yours?
Cheers!