My '02 Sonata's power antenna doesn't like extreme cold. When cold it
oftens "clicks" when going up or down. Now it doesn't do anything at all.
Thoughts???

 

You can try lubing it with a silicon-based gel or some white lithium grease
to help it move better. I suspect some clicking will always remain.

 

Oops. Missed the "doesn't do anything at all." You may need to try to put
it in a heated garage to warm it, get it to operate, and then lube it. If
you can't do that, there may be some actual problem with the antenna that
needs fixing.