Tailgate rust - possible cause

[tony_ack 0]

I've seen a few Corrados (including my own) which seem to rust from around the number plate light area in the middle of the tailgate. I got a replacement yesterday which looks fine on the outside, but again there is some surface rust on the inside around this area. We thought it was the screws for the plinth, but I've had a closer look now, and I think there is something else that causes this.

 

The number plate light bulbs are bare inside the tailgate (i.e. they're not enclosed seperately) and are very close to the inside of the panel. The rust looks like it started from immediately behind the bulbs, so I wonder if the heat from the bulbs has either melted the paint, of repeated expansion/contraction of the metal has caused the paint to crack, exposing the bare metal?

 

If this is the case it may be worth getting some high-temp paint down there on the inside of the tailgate after clearing the rust. If your Corrado is fine in that area, it may still be worth a look as there may be some rust on the inside you can't see.

[VW_OwneR_85 2]

i remember being told at college that heat speeds up the corrosion proccess, i guess heat proof paint wouldnt hurt,

[dukest 0]

i think you're right in that its more common than people think but they just dont realise it because its not visible when the spoiler's down. mine has it but doesnt seem to be getting significantly worse so havent fixed it yet but probably should do one day...

[James. 9]

The rear light has a foam seal that retains water and other nasties. This over time bubbles from the inner lip and moves further up the body.

 

I found replacing the seal, inserting plastic screws to reduce corrosion, remove the light and bladder wax round the openings along with raising the spoiler when cleaning/washing can help a great deal though.