Trunk Lid Organizer

While driving cross country in my new car I narrowly avoided a multi-car accident and found myself first on the scene. By sheer luck my first aid kit was wedged in the front corner of the trunk between luggage and was easy to find. I decided that I wanted a better way to ensure my emergency tools would always be where I could easily find them.

On this car (a Toyota GR86) the trunk lid hinges operate in a way that when open, all the weight of the trunk lid sits behind the hinges, so I can add a fair amount of weight before there's any problem with the trunk staying open. On other models this may not work as well, or require changing the hydraulic lifters to something with more power to hold the trunk open. In any case, my plan wasn't to add very much weight anyway, so something like what I've done should work for most cars with trunks.

I do plan to take a strip of flexible edge protection around the perimeter of the board at some point to give it a cleaner look.

You can build this with any kind of pegboard or similar solution you'd like. I assume that I'll want to change something at some point, so pegboard was an obvious choice for versatility, and the Ikea SKÅDIS pegboard has slots instead of round holes, which comes in really handy for this design. I got a much larger sheet than I needed because I expected to need enough material to make at least two versions before I got it right.

https://www.ikea.com/us/en/p/skadis-pegboard-combination-white-s09216595/

You'll also want to get the bungee cords for this (I don't believe it would be easy to get them hooked into a standard pegboard, btw.)

https://www.ikea.com/us/en/p/skadis-elastic-cord-gray-40321631/

There are also a couple different 3D printed parts I used. I'll cover them on the step that uses them. (I recommend something reasonably high-temp, as auto interiors can get extremely hot in sunlight.)

They're sized for M4 bolts, you'll need half a dozen or so of those in 8mm-10mm length (each spacer needs 2, and depending on the thickness of your liner you probably don't want both of them to be 10mm long). You'll need some washers as well - fairly large outside diameter. Finally, you will want some adhesive felt tape or similar protective material to prevent the metal bolts from rubbing on the auto paint.

I removed the liner/"skin" from the underside of the trunk lid, and traced it onto the cardboard box the pegboard came in.

Note, the method of attaching this liner to the vehicle may vary by manufacturer, but it's generally with plastic trim fasteners. They're cheap to replace if you break one, but with a trim-removal tool or simply being careful you can usually get them out without breaking them.

The cardboard tracing doesn't have to be perfect, but it needs to be really close. Cut it out and then test fit it on the trunk liner. Make any trims/adjustments you need to. Then take your time and make sure you find the absolute middle of your template because the easiest way to make it symmetrical is to use the same side of the template for tracing the pattern onto the pegboard. (See the first picture, the vertical line is the centerline of my template.)

Next, you'll need to attach the template to the pegboard in a secure way. I knew I wanted to use spacers to provide standoff room between the pegboard and the trunk lid liner (otherwise there'd be no room for the hooks to "hook" behind the pegboard). So I designed and printed a couple of them (file attached). Pop one in the center of the pegboard and then use an M4 bolt carefully poked through the centerline of the template. Do this again further down the template so it's held in place on the pegboard securely.

Trace one half of the template onto the pegboard, then flip the template over and trace the other half (using the same side of the cardboard.)

Or trace it however you like. The main point is to get the shape accurately transferred to the pegboard so you can cut it out and have it look acceptably nice.

I used a hand-held jigsaw to cut the pegboard - be aware that though it looks like it's made of plastic, it's more like hardboard with a plastic-like white paint on it. You'll also want to chamfer the edges to clean them up and make them friendlier to the touch. Do a quick test-fit on your trunk lid liner, then off to paint! (optional)

I'm not an expert on painting things. I had a rattle-can of blue spray paint in the cabinet and I just shot the pegboard with two coats on two days.

I do know this: give it longer than you think it needs to cure. Paint goes through many stages. After it's no longer wet it will still be slightly sticky or "tacky" - that's not actually dry. Then after more time it will stop feeling slightly sticky to the touch, but it's not fully hardened. Still not cured. Finally, after more time it will fully harden. When it's not tacky anymore you can handle and work with the piece, but be really careful because it's easy to chip or peel the paint. Don't really "use" it until it's had a few days to completely cure - that's when the paint will get as strong as it can.

Decide where you want the standoffs to be. They should be in locations to make the board stable/strong, but also not significantly interfere with the function of the board - any place you put a standoff is going to be a slot on the pegboard you can't use for mounting stuff. Also make sure they won't interfere with the holes where the trim fasteners go to hold the liner to the car.

I recommend a little bit from the edges. They friction fit really well for me so I was able to move them around and they'd stay in place while I put the board on the trunk lid liner and tried pressing down to check for excess flexing. A little flex is fine, you just don't want it to be wobbly. I went with two spacers on each end, and one in the middle.

Once I was happy with the placement of the spacers, I centered up the pegboard exactly where I wanted it and used a rat-tail file to carefully poke a hole through the liner through the center hole of the spacer. I then put a washer on a flat-head 8mm M4 bolt, pushed that through the hole, and snugged it down to the spacer on the other side. (It may be helpful to "pre-thread" the spacers by running a longer M4 bolt all the way through them beforehand.)

Repeat this for each spacer, being careful to be sure the pegboard is flat and centered the whole time so the spacers are exactly where they should be. Finish up by covering the heads of the bolts on the back side of the liner with a piece of felt, rubber, or other adhesive protector (so that when you reinstall the liner those metal bolt heads can't damage your paint.)

Reinstalling the trunk liner on the car should be simple. Pop your trim fasteners back in and make sure the liner is back in place.

If you used 8mm bolts on the back sides of the standoffs, or longer bolts because your liner was particularly thick, you should be good with using 10mm bolts on the front to mount the pegboard. The slotted shape of the standoff is going to be slightly weaker than the main round part of the body when it comes to gripping the threads of the bolt. It probably doesn't matter, but I wanted to make sure I had at least a few millimeters of bolt that extended into the main body.

The slot is important because it fits into the pegboard and eliminates any worries about a bolt going part way in and then the standoff spinning behind the board and not allowing you to get things properly tight.

Use washers large enough to give a good grip on the front of the pegboard (I'm not sure what size the ones I used were - they're just some spares I had in my "Washers" bin.) The bolts were 10mm M4 flat heads. The pegboard should fit perfectly and bolt right up.

The beauty here is that you can easily assemble/disassemble the whole thing any time you need to, and if you completely remove it the holes the M4 bolts put in the liner are difficult to see and you can "massage" the liner to make them practically disappear.

The final component is the "pegboard bungee hook". This is a part intended to secure the bungee cords at any point between the ends. If you look closely in the final picture you can see that the orange "LED roadside flares" on either side are held by a single bungee each, with a small lighter blue hook underneath pinning it place. Since the bungees themselves come in one length only, this adds the versatility to hold smaller objects that would otherwise be difficult/impossible to secure to the pegboard.

For those unfamiliar with 3D printing, they're flat on one side to make FDM printing easy, and should be printed in that orientation for maximum strength.