Burning smell

I have noticed recently with colder weather and wet roads after driving on the expressway a burning smell. I do not notice this while driving on regular roads where the speed limits are slower. Normally have the heat on, have to shut it off and open the window. After a bit the order goes away.

SEARCH burning smell...............and..........ya get:  BURNING SMELL FROM MY ENGINE?
 
We gotta work a little harder on serching before posting gang, and believe me this is not directed just at you jwiz.  

Also search "Burning smell coming from vents"