Meh. I don't have fenders on my folder either. Rain shmain. Yer either gonna get wet or you aren't. Maybe if I were going through mud or something. (my rear rack does a reasonable job as a fender anyway)
Good on ya' for making the order. I'm a big fan of CrMo over Aluminum and you're getting an awesome frame you can do what you want with, if you even WANT to upgrade it. (you might find it does the trick right out of the box)
For free upgrades: drive around the evening before garbage day. I found a Shimano S3 internal hub this week and a funky chrome chain/spoke disc.
You might be able to get the "Magnetix" widgets direct from Dahon. Don't they just screw into the eyelets near the rear axle?