So i noticed in the spare tyre well there are 2 large plugs in the bottom and a smaller one. What is the purpose of these. I understand one is to let water out. But is it ok to seal these up? I found that one had popped off so i wanted to know if i could seal them up.

If you seal them up and you get water in there how do you expect to get the water or what other liquids that may spill in your boot out, go to a wreckers and grab some more, they probably won't even charge you.

If you seal them up and you get water in there how do you expect to get the water or what other liquids that may spill in your boot out

Paper towel?

They are there to drain cleaning fluids and the wet electrocoat out of the body in white paint preparation and first paint processes.
If the plug is missing just tape over the hole with gaffer tape.
Gerry

If you seal them up and you get water in there how do you expect to get the water or what other liquids that may spill in your boot out, go to a wreckers and grab some more, they probably won't even charge you.

There are several ways to get the liquids out i would assume. None i can think of are particularly hard. But they would be a little time consuming. But if i'm going to have a whole bunch of electrical stuff in there wouldn't it be smart to seal them. And i never said i lost a plug =) i just said it popped out. To make things clear it popped into the wheel well itself. So i still have it. But i just don't want to have them doing that often if I'm going to have electrical stuff like subs lights and stuff in it.

It sounds like an excellent way to get dust into your boot space if you have a dirty big hole in the spare wheel well. Tape it up. Make sure that you don't spill stuff inside the car and you shouldhave no problems.

Just coat the old plug with silicone sealant and reinstal - it will stay in more firmly.