Caveat up front - BEFORE YOU GO BUY A NEW FILTER FROM THE DEALER, LOOK AT THE OLD ONE AND TRY TO CLEAN IT UP IF POSSIBLE. THEY COST $42.99 + TAX! (Part Number MR500360)
I've been meaning to do this for a while. I have a '00 GT with just under 60K miles, and it has never been done. So while I was back stateside for my sister's wedding, I stopped by the Mitsubishi dealer to pick one up. I figured I had flown halfway around the world to go to the dealership, so I was commited despite the $42 cost. It is not too impressive looking, and I figured it was probably the stupidest money I had ever spent on a car:

However, after I got the old one out, I figure it might not have been such a waste of time after all. Still, see above. I would take a look to see how bad yours is, and make a concerted effort to clean it before shelling out the cash. Here's the 6 year old filter:

OK, here's the step-by-step. It is really easy once you know how to do it. Probably a ten minute job with a phillips head screw driver.
1. Take everything out of the glove box.
2. There are two pieces to the glove box - inner and outer. There are tabs on either side of the inner glove box (see pic). Just bend the box to get those tabs through the outer glove box. The entire inner glove box will them swing freely down into the footwell, and fall (or lift) right off the hinges.

3. There are four (4) brass screws holding the outer glove box into the dashboard. You can see them in the pic below. This was taken from the floor, looking up:

4. After the screws are removed, grab the forward, lower edge and pull down and back. The entire thing should come out very easily. Here's a picture of the whole thing removed:

5. The filter is held in with two small screws. When you pull it out, you'll need to work it a little around the dash, but it came out and went back in without any real difficulty.

6. Reassemble. Ahh, clean air!
7. I took the old filter and vaccuumed it, then ran water through it from the back side, like an oiled filter. After letting it dry it looks to be in passable shape. The filter element slides easily out of the plastic frame, so you can get the crude out of it pretty well. I think it is reusable, certainly when a new one will be $42.

I've been meaning to do this for a while. I have a '00 GT with just under 60K miles, and it has never been done. So while I was back stateside for my sister's wedding, I stopped by the Mitsubishi dealer to pick one up. I figured I had flown halfway around the world to go to the dealership, so I was commited despite the $42 cost. It is not too impressive looking, and I figured it was probably the stupidest money I had ever spent on a car:

However, after I got the old one out, I figure it might not have been such a waste of time after all. Still, see above. I would take a look to see how bad yours is, and make a concerted effort to clean it before shelling out the cash. Here's the 6 year old filter:

OK, here's the step-by-step. It is really easy once you know how to do it. Probably a ten minute job with a phillips head screw driver.
1. Take everything out of the glove box.
2. There are two pieces to the glove box - inner and outer. There are tabs on either side of the inner glove box (see pic). Just bend the box to get those tabs through the outer glove box. The entire inner glove box will them swing freely down into the footwell, and fall (or lift) right off the hinges.

3. There are four (4) brass screws holding the outer glove box into the dashboard. You can see them in the pic below. This was taken from the floor, looking up:

4. After the screws are removed, grab the forward, lower edge and pull down and back. The entire thing should come out very easily. Here's a picture of the whole thing removed:

5. The filter is held in with two small screws. When you pull it out, you'll need to work it a little around the dash, but it came out and went back in without any real difficulty.

6. Reassemble. Ahh, clean air!
7. I took the old filter and vaccuumed it, then ran water through it from the back side, like an oiled filter. After letting it dry it looks to be in passable shape. The filter element slides easily out of the plastic frame, so you can get the crude out of it pretty well. I think it is reusable, certainly when a new one will be $42.
