The cold gets really old really fast. I'm fine in 20-30 degree weather but below zero blows. I run 5w-30 Mobil 1 and the stuff still gets really thick.
Sadly, they have been. I don't know how long parts will be available but sooner or later I'm going to have to switch to an LST XXL. The arms are about the only thing they share, maybe driveshafts (obviously not centers, but the wheel axles should fit). The diffs are a different ratio between the Muggy and LST, the LST has aluminum bodied shocks rather than the plastic Muggy shocks, the LST comes with aluminum diff cases where the Muggy comes with plastic. It's really unfortunate but they only sold it as an RTR and at $500 RTR they weren't too popular.
EDIT: The shock towers and body mounts are the same, forgot about those