I only have limited personal experience drying wet lamps... but for headlights, you might popping out the lamps, seal the garage and start up a good dehumidifier. I know moisture in the headlight can lead to big bucks repairs if they are metal and left moist. Even then, the reflectors may never be the same if the water was murky and enough got in to leave a film. Another idea just popped into my brain - I know you can buy little packets of silica gel to keep things dry. Or that crystal cat litter is the same stuff, just need a way to contain it in the headlight for a day or three.