Condensation build up on inside of rear light on RX8

In regards to condensation/water buildup in rear lamp assembly of 2004 RX-8; the problem is defective gaskets. They degrade over time and fall apart. If your vehicle is still under warranty the dealership will replace the gaskets as per recall. Since it is not a safety issue, as my dealer told me, if your warranty has expired you can purchase new gaskets (around $40 each) or remove the tail lights yourself and apply silcone or rubber gasket sealant to the old gasket (inquire with a body shop as to what to use, I used Permatex ULTRA Rubber Gasket Sealant & Dressing).WARNING: Do not use solvents of any type to assist in the removal water/condensation for light assembly as solvents will dry out the lens and crack them: which is what happened to me, however a few days later my neighbor hit my car and damaged the light so I had it replaced. Handle the light assembly carefully as they can crack easily.

Take rear light out by removing back trim grub screws, unplug all electrical connectors to bulbs (use small screwdriver to prise connection away from bulb) then undo 10mm nuts, 2 on left side 4 on right leaving boot lid lock barrel in place (best to put a nut back on this one to hold in place to shut boot lid,, remove bulbs and empty as much water as you possibly can from the units by shaking downwards, then put them either over central heating boiler (worked for me) or anywhere where you have heat rising (immersion cupboard etc.) and the rest of "fogging" will disappear, I put poly bags in holes left in boot lid just to stop any rain getting into boot, hope this helps, good luck

Cheap way is to use plumbers putty £3 a tub and once you have drained the water out , use this to put around the top edge of the gasket ( where it meets the plastic ) and also create a rain channel on the back of the car , you will be able so see where the gasket fits cause of the dust residue, create a lip from the boot lid channel between the two lights (its roughly centre) . good look it cost £3 plus an hour of your time.

My son and I both have 2004 RX8s. We have both had problems with condensation build up in our tail lights(4-5 times each. The tail light has to be remomed, interior dried reseasled, and reinstalled. So far we have been lucky enough for the worh to be covered by warrantee..