Just purchased 2002 C4 cab, not here yet. Noticed on test drive that the seat heaters work well, but seem to have two settings: one shows red led's lit, one more push shows yellow led's lit. Can I conclude that yellow is warm, and red is full on?

 

Yes, you are spot on.

 

I recall the first time I saw the 996 seat heater switch, I thought it was only an on/off switch, so what a pleasant surprise to find that it has that low/high setting!