Duster Rear-Defroster/Defogger?

the front air is warm enough...it just doesnt have any power.....it like low and medium speed....a cigar lighter could work if the element was engaged all the time (pressed down) and as log as it was contained it should be ok. it wouldnt be on for more than ten minutes....is there another way to get a cigarette lighter to do this...or something safer

ive seen a defogger that fits my car....it just doesnt look clean for a 69 dart