Sounds like 303 Aerospace Protectant would do the job for seals - it's got PMDS in it.OP, grab some silicon spray and have at the weatherstriping. I usually do it twice each winter - once in Nov, again in Jan - and have never had frozen doors / trunk.
For the locks, I use graphite spray rather than either WD40 or silicon since those will allow dirt/grime to accumulate.
