I have noticed a leak in a hole from the back of the boot. In the pictures I have roughly pointed out arrows where these holes are.

As you can see it seems one of the holes(which is not leaking has a plastic cover) and the other has no cover and it is leaking.

  1. What is the purpose of this hole and what is it/the lid called.

I tried to remove the plastic cover on the non leaking hold but couldn't get it off.

  1. Is it simply a case of getting this part and sticking it on like a lid, as I couldn't take the other off I imagine it is added a different way?

  2. Are there alternative ways quick ways I may be able to fix/block it?

  3. I imagine putting the lid is the correct way to fix it or is one of these meant to have no lid in which case does the metal need to be removed to find the origin of the leak?

boot hole points empty hole covered hole

1 Answer 1


In the process of building a car, you take a whole bunch of stamped sheet metal components, fixture those sheet metal parts into to a precise location then spot weld the components together to form the shape of the car's autobody. The easiest way to fixture parts accurately is to use punched holes and slots as locators for pins in the weld fixtures.

Weld fixture

Remember when your car is welded up, those panels must be accurately located to the nearest 0.2mm or better. (My best guess... depending on which part of the car we're talking..) Generally those holes are located in dry zones within the vehicle shell. If the hole happens to be on an outer panel and a water tight seal is required, the automotive manufacturer will use a rubber or plastic grommet (plug) to seal up the hole. Those grommets tend to be hand installed at the vehicle assembly plant after sheet metal is welded.

automotive weld fixture

It looks like somebody missed that plug on your rear trunk inner panel. You can remove the plastic rear cover from the trunk, accurately measure the size of the open hole, then order a replacement grommet / plug (either from your local autoparts store, or directly from the dealer.) As I examine the photo of the hole in your sheet metal, it looks like there was a plug installed at one time... I can see the hint of black line where the edge of a grommet would sit. Could someone have remove it for some reason? Perhaps it was partially installed and fell out later? At the the automotive plants I've worked, they did do a 100% test for issues like this.. we used a water booth system where every car was sprayed as though in a hurricane rainstorm for five minutes, then they'd inspect for leaks inside the car. If totally missing, this would have been caught for sure.

Body Plugs

If the car is new, this should definitely be covered under warranty.

Note: sometimes you will see a wire harness pass through these holes, with a molded on grommet already on the wire harness. Note2: They've been using this stamped hole / grommet seal technique for more than 50 years or so.

  • Maybe you can find that grommet at the junk yard.
    – Bob S.
    Mar 12, 2019 at 6:15

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