Applying engine dressing

I was thinking about applying some WD-40 to all my plastic and rubber. How long do i have to wait after driving the car to be totally safe. I dont want to do it when its hot so how long would u recomend???? And how long does this stuff last.

don't do it, you always get it on the paint and it is hard to get off,and wd-40 attracts dust majorly!!

I use a good silicone spray, you know the one, it also comes in wipes, which keeps it off the paint ;)
Makes everything look shiny and new. Lasts for months.