Dead Rat Odor Removal?

The dryer sheets were an attempt to prevent mice and rats from moving in - its a common technique for vintage vehicles. Obviously it didn't work that well in this case. I've restored old vehicles that had rodent infestations and the only real way to get rid of all the odor is to remove any porous material that soaked up the now-liquefied rodent corpse. Heat will always bring up the odor even years after the remains have been removed. My suggestion would be to expose as much of the infested area as possible and clean it with bleach where possible, and replace anything porous (wood, carpet, pads, insulation,etc.) that you can.