Normally, I'd come back like you guys and say I'd noticed no problems with condensation - but NEVER again. Last winter I left the NX2000 in my enclosed trailer, partially disassembled, with a lot of loose parts (engine stuff, mostly) in the hatch and passenger floor area.
Didn't think much of it until March rolled around and we grabbed it to bring it to Matt's shop for the season. When I opened up the trailer, I was horrified: EVERY bit of exposed metal had significant surface rust. Struts, rotors, brakes, MY NEW CAMSHAFTS - everything. And this wasn't basic surface rust, either; the cams were pitted badly enough that I had to throw them away...
I have a different trailer this year but I'm not taking any chances; this year things will be different. I've purchased a controllable dehumidifier, one where you can set the humidity level and it'll cycle on and off, and that's now in the trailer. I'll be consistently going in there and checking for any kind of rust and/or corrosion. If necessary, I'll buy a small thermostatically-controlled electric space heater and plug that in, too.
For what it cost me in lost parts and rework, the cost of a dehumidifier and heater are peanuts...
Greg, CT