id use 10.1 apc to remove any old product from the dash, them autoglym vinyl and rubber care applied using a sponge and buffed off with a clean short pile mf cloth.
david
i think its a nissan thing to be fair, my 99' almera GTi does this too. i tend to lower the windows about 20-25mm and lock the car, this helps the warm air escape. i have dark wind deflectors so you wouldn't tell from the outside.
david