yesterday was the first heavy rain in a while, i was driving on the freeway as it was raining then exited and came to a stop (idle at 800 rpm), i tried to crack the window for some fresh air (pressing down all four automatic window buttons, the idle went down to about 500-600 felt like the engine wanted to stall then bounced back up to 1000 then to 800, again i press down all four buttons and same thing happened. the engine never stalled completely. everything else worked ok (speakers, lights, etc. wasnt flickering) i drive a 08 sl manual. i have no clue what would be causing this, any thoughts or suggestions on what to do??? sorry for the long post.