I’ve written about a lot of tools this year . Some of them have been obscure and arguably only sometimes useful. Others are gadgets that you shouldn’t leave home without. Let’s review the coolest and most useful tools we’ve seen this year.

The Cool Tool series has opened my eyes to tools that I didn’t know existed and has made wrenching better for me. There is something to be said about working smarter, not rounding bolts with the wrong tool or guessing what could be wrong with an electrical system. I know my cars are likely happier for it, too.

Most of the tools featured on Cool Tool have been suggested by you, the lovely readers. Others have been tools I already own or have discovered when trying to solve problems usually related to Smarts and Volkswagens. Some of you have been emailing me with tools to feature in future entries. Many of the suggestions have been tools that I’ve featured in entries early this year.

You know what sucks? Either dealing with a very long bolt or more bolts holding onto a single part than you can imagine. Getting a bolt loose can be hard enough, but you’ll sit there with your ratchet going back and forth, back and forth until the bolt is finally free. If you’re dealing with a big part, like the underbody pans of a modern car, now you have to repeat the process for a dozen, if not more bolts. The time spent simply removing bolts adds up.

My view on jobs involving lots of fasteners was changed when I picked up a friend’s cordless ratchet and simply zipped those bolts off. No more sitting there thinking “how in the hell is this bolt so long?” because the cordless ratchet is doing all the work, and doing it fast.

This suggestion came from a number of readers.

A number of modern cars come with “sealed” transmissions that do not have easy-to-access fill ports or even a dipstick to check fluid levels. Other vehicles have differentials, transfer cases and other parts that have fill ports, but they aren’t placed where you can simply shove a funnel in there and pour fluid down the hatch.

If you’re like me and you have some absurd cars in your fleet, your engine oil pan may not even have a drain plug, so oil has to be sucked out of the engine.

In these situations, you need a fluid transfer pump to get the job done. They’re simple tools that create a vacuum to suck fluid out of one area to deposit it into another.

This suggestion was recommended by a number of readers, my mechanic, my toolbox and Opposite-lock .

A number of modern cars come without the gauges that show critical data about your car’s health. For example, the second-generation of the Smart Fortwo doesn’t have a coolant temperature gauge. That’s bad enough, but the coolant temperature warning light doesn’t illuminate until about only 10 degrees before engine damage begins occurring. Usually, by the time the light actually comes on your engine is already toast.

That’s what makes an OBD-II monitor such a handy tool. These tools come in a bunch of varieties, but they all do about the same thing: Let you know what your car knows.

This suggestion comes from my own toolbox and I think everyone with a car missing vital gauges should have one.

The pandemic has led to a change in how people live. The rise of work from home and delivery services mean that some of us aren’t driving like they used to. For me, some of my cars sit just long enough for their batteries to expire. I got fed up with that and started searching for a solution that didn’t require plugging the car into a wall.

I landed on a solar panel car battery maintainer . As the name suggests, this tool keeps your battery topped up while you aren’t driving your car using the power of the sun. I actually bought one and thus far it’s doing its job smashingly well.

This suggestion came from my own desperate searching for a solution.

The multimeter is a tool that every gearhead should already have, yet I think it deserves a mention. Until I picked up a multimeter I simply guessed what was wrong with an electrical system. This was until I hit a roadblock in figuring out what’s wrong with my Triumph Tiger’s electrical system. A multimeter turned what was a mystery over months into a solution found in about an hour.

Stop wasting time trying to guess electrical issues and just pick up a multimeter, you won’t regret it.

This suggestion came from my own toolbox.

Have you ever tightened a fastener just for it to suddenly become “righty-loosey?” There’s a dreadful sinking feeling that accompanies that situation. Stripping out a threaded hole means your day just got a lot worse (and longer).

Now, there are a variety of ways to fix it. You can just use a bigger bolt or even deploy self-tapping screws. But there’s a neat tool out there that puts the self-tapping screw to shame. The rivet nut (also known as RivNut or Nutsert by their commercial names) is a rivet and a nut in one. They consist of metal fasteners with internal threads and a shank. These are great for making new, clean threads in plastic, fiberglass and thin metals.

This recommendation came from NickHasCars and numerous other readers.

There’s a joke among those who wrench and it’s that the 10 mm socket will always find a way to disappear. So many parts have 10 mm fasteners and that darned socket is never where you last left it.

If you’re working on a big enough job, chances are you have a bunch of tools and fasteners splayed out all over the place. Move around just a little and it’s easy to lose track of where you left something. I’m sure everyone has dealt with a tool falling into an engine bay and not coming out the other side.

That’s where a silicone tool tray can help. Slap this baby onto the top of your engine or the canopy of a fighter jet and now you have a nice and secure place to keep track of your tools and fasteners. The brand name version of these is called Grypmat—a creation of a fighter jet mechanic who lost some expensive tools and small parts while fixing aircraft.

This suggestion came from the wonderful people of Opposite-Lock .

Some cars have cooling systems that are unforgiving to even minor mistakes. And when something goes wrong, it can lead to one of the worst days you’ll have as a car enthusiast. As an example of what could go wrong if you aren’t careful with a cooling system, look no further than my fiancee’s Oldsmobile LSS. Some questionable repair work led to the car drinking its own coolant to the point of hydrolocking and cracking the engine block.

If you’re a Volkswagen masochist, then getting air bubbles out of your cooling system may require a delicate act of opening valves throughout the cooling system. And even then, if you get it wrong, your car can overheat.

A good way to reduce the chances of something going wrong is to use a vacuum purge and refill kit . You could replace your coolant yourself, then bleed air bubbles by following a service manual or parking the car a certain way. Or you can let this tool do it for you. They work by using vacuum to replace the air in your cooling system with fresh coolant. These can even be used to check for leaks.

This tool was suggested by follow Volkswagen masochist Dieseldub.

Wrenching is a dirty job. If you don’t get covered in some awful fluid like burned gear oil (I don’t recommend it) maybe your tools or your parts do. This is even worse if you live where roads get salted. Some of the most gnarly-looking parts I’ve seen have been on cars living a hard life in the Midwest.

You could clean up the gunk by hand, or you can let ultrasonic waves do it for you. Put those dirty parts and tools into an ultrasonic cleaner and enjoy hands-off cleaning. Ultrasonic cleaners can also give old jewelry a new shine and even clean up medical equipment, too.

This suggestion came from a number of readers responding to the parts washer entry.

One of the biggest turn-offs about a car can be how it smells. You can find a bucket list car for sale then decide it’s not for you because the interior smells like someone crapped their pants in it. Or maybe you picked up a barn find and found that some critters have left a nasty surprise for you. Or maybe you’re a non-smoker hit with a huge smoking fee from Hertz .

When a car smells absolutely awful and a regular cleaning doesn’t get it out, it’s time to deploy an ozone generator . These machines use an electrical discharge to break oxygen molecules into single atoms, which then combine with other oxygen molecules to create ozone. That ozone then reacts to pollutants in a car and is meant to break them down through oxidation.

This was suggested by many readers in the aforementioned Hertz story.

Those are the tools that I think could help wrenchers the most this year. Some of them are must-haves, others just make your day and your life easier. I got to try out a number of new tools this year as well, like a battery power station that I’m testing right now.

Have you bought a tool or a few because of this series? I’d love to know what has helped you! Otherwise, keep those tool recommendations coming.