Every once and awhile at a stop light my car idles real rough, and the gauges and headlights start dimming. I think its the alternator, others say its the tranny from taking it to the track alot. What do yall think?

 

tranny would have nothing to do with lights dimming and such even if the car is about to die it wouldnt start to cut the power for the lights and such.

 

I say plugs, battery maybr the alternator

 

any codes or CEL? I would say alternator ...