so my 88 IROC vert has 2 cigarette lighters - one ?added to the lower part of that panel with the rear defrost delete. Almost looks factory except the lighter itself is plain. May I assume that it's an aftermarket add-on or did they actually make dual lighter cars?

 

It's been added later by a previous owner. He/she may have wanted an extra power port for more accessories (radar detector, to charge things like cellphone or MP3 player, etc) or to allow the use of the cigarette lighter without having to unplug one of those accessories.
Or maybe they were just heavy chainsmokers!!!!
All the 3rd gens had only one cigeratte lighter.