Sounds like someone went a little nuts with an impact gun. I find it very hard to beleive they will corrode on that bad over just a few months; I have never had that happen on any of my cars. I always tighten all my wheels with a torque wrench to 80ft pounds, and the bolts always break free with my 1/2 breaker bar, even on my SD where they were on for two solid years and two salty winters. However I have had the pleasure of fighting with broken stud's and stripped nuts, when some moron uses an impact gun set to max.
When you do get them off, this is your new best friend! In salty climates you can't get stuff apart without it!
