6 month review:
Gen2 2006 Prius has no room for any catch can at the upper throttle body level. Installed it in a small space just behind the bottom of the radiator, roughly center. Can is accessed from below the engine near the oil filter. Works fine. Bought quality hose from Napa. In this install the original hose exits the PCV valve horizontal then drops about 18" to the can. Then exits the can and rises about 18" to the bottom of the throttle body. The can was mounted using a custom bent L bracket connected to near the radiator frame. One advantage to this install may be gravity. Fluids naturally flow from either direction to the can.

This Prius used about 1 qt 5W30 every 1300 miles. The throttle body lower was routinely wet with puddled clean oil. Two can clean outs over 6 months produced about 200mls of clear watery non-flammable liquid and a small amount of yellowish globs of higher density. Little or no apparent oil as was expected.

Conclusion:
For some odd reason the oil stink the car once had seems less or none. Not sure why. Also, the oil seems cleaner on the dipstick after 6 months and smells normal. The oil usage is far less as well. Not at all sure why?????? The question is where was the throttle body oil coming from and why. It was assumed from the PCV system. It would appear the oil may have been coming from the engine side of the throttle body? It is unclear how the catch can could be lowering oil usage and making the oil cleaner???????

The can itself is well made. The kit included steel wool. It may be best to avoid this like the plague. It is magnetic and has lots of tiny fragments that could easy get sucked into the throttle body then the valves. Even one frag in a valve could be really bad for the seat or the seal. It's just not worth the risk The Can works fine without it especially if using gravity. Added Vaseline to the threads and oring.

I was very skeptical about trying this inexpensive oil catch can from a few other reviews, but I'm glad I did.
I just completed a manifold replacement and my old, original manifold, had at least a quart of oil sloshing around in it! And, it had leaked out making me think I had an oil leak! All from the PCV valve carrying heavy oil/gas vapor back into the manifold to get dumped back into the intake manifold and only partially burned...what a terrible thing to do to a throttle body, intake manifold and engine!
So I looked for a inexpensive oil catch can to try.

It's actually very good quality. The other reviews I read said to throw away the hose that comes with it. Well, they must have upgraded the hose to some good, steel braided hose, with a nylon weaved sheath. Very nice, and it looks good too. I used a large electrical cable lopper to cut it. The braid is sharp edged, be careful.
I did throw away the small hose clamps, as not needed, but they did seems rather cheap in quality, but the can itself has a nice screw on bottom with an o-ring to seal it. I recommend you grease it lightly to keep from tearing it when tightening and loosening it.
I did not use the included aluminum mounting bracket, as I needed a small custom mount for it, but it was nicely coated black. No matter what vehicle you have, you WILL have to get creative and find a place and a way to mount this. Keep your hose runs as short as possible.
The can itself is anodized aluminum, so it will not rub off like paint.

The last thing I did was to add a small o-ring to better seal the dipstick and I used Permatex liquid thread sealant on the hose barbs. It comes with three different sizes of hose barbs. The medium size barbs fit tightly on the included hose just fine. I saw no need for a hose clamp on them. It's only a slight vacuum after all.
I was able to push the braided hoses into the 70 degree corner hose adapter fittings that came on my engine. (PCV valve output and manifold input)
The catch can has markings for input and output.
I'll update the review when I catch some oil with it. It HAS to work. You know, physics..

(UPDATE: After just 350 miles it has collected about a tablespoon or more of oil! (.5+ oz)
This is outstanding. This equates to about a quart of oil per 20,000 mi. being poured down your throttle body and into your intake manifold. SO glad I bought and did this addition! )

If you have a space for it, it's an easy install. You'll probably need to get some of your own hose to complete the installation.
The fittings seem cheap but they are not under any real pressure so they're not in any danger of leaking. Multiple sizes of fittings are included so you can run whatever size hose you want. I installed mine on a husqvarna fs7000d (3.2L turbodiesel) concrete saw at work and a 2013 Chevy Captiva Sport (2.4L direct injected gas engine). Both are working great.
You'll need a drill to make mounting holes and some hose to run the lines. I used black rubber fuel hose. You can use hose clamps if you wish but they're not under much pressure so it should seal fine without.
One line goes to a PCV valve or breather and into the catch can. The other goes from the catch can to your intake tubing between the throttle body and the air filter.
I mounted the catch can on the passenger side wheelwell behind the engine. It was a tight install but it is hidden and works well. I drain it every oil change unless it is very wet weather and then I drain it more often. You won't believe the crap that it filters out of your engine. A yellowish, oily, watery mix. I'm glad that's not gumming up my intake valves.
On the concrete saw, I mostly use it as a breather. If I turn up the boost pressure for running a bigger blade, it relieves the excess crankcase pressure into the intake tract instead of blowing a gasket or oil seal.

Installed this on a 2011 Buick Enclave with the 3.6 L V6 with direct injection, which are known to have intake carboning up issues due to direct injection. A catch can may eliminate these issues.
This catch can is built really good for being less than $30. It does a great job of catching all of the moisture, and crap that would otherwise be inside the engine. It's kind of unsettling seeing all the crap that it catches, knowing that was all in the engine! I'd recommend this product to anyone.

BUT, there are a few "gotchas" that I have learned"
Don't over tighten it, or it will be extremely hard to get off. In order to prevent issues getting it off, I spin it on fully, and as soon as it "bottoms out", (stops turning), I back it off about 1/2 or 1/4 turn. Otherwise, it will get on there extremely tight, and we have had to put it in a vise to get it off once when I tightened it all the way. I also put some grease on the threads to help it spin easily. Doing that, it comes off easily, and it doesn't leak.
This kit did not come with any instructions, or any substantial mounting hardware. We had to use a scrap piece of aluminum to mount it, some custom fabrication was needed (nothing major though, just bent and drilled some aluminum.) And secured the catch can to it using some fasteners we had around. The hose that comes with the kit, I would not recommend using. It is just too thin, and I wouldn't expect it to last a long time. I used some 3/8" heater hose from a local auto parts store, and that works great. (May have to use different depending on your engine). The thread sealing tape that comes with the kit isn't that great either, so I used some better teflon tape.
Otherwise, this is a great product.

First off, the kit did not come with instructions. That being said, the install is fairly straightforward albeit takes some fabricating skills. Plan where you want to install them before hand. More than likely you will have to fashion a bracket to mount them to and every vehicle is different. In my case, I placed them near the firewall and used adjustable shelving rail to make brackets that allowed me to use existing fasteners. The steel wool goes inside the can, just place it in the can and make sure there is a half inch or so of space above the wool to the lip. Removing the dipstick from the can will also make it easier to screw the can on. Another note is that the included teflon tape, hose clamps and hose are junk. For the hose, it is made of soft rubber and is way too short. I bought 10ft of 3/4" vacuum/fuel hose from O'Reilly's and ended up using around 8ft total. You can also get good quality hose clamps there as well. Each kit only gives you two and you need 4 total for each can, additionally they deformed and fell apart when I tried to tighten them. Each kit comes with a variety of nipples that will allow for a variety of hose types which was nice. I was also able to remove the factory connectors from the original hoses and use them with the new hoses which definitely made installation simpler. I would definitely purchase a can for each path that your vehicles PCV system has. In the case of my 2014 F150 Ecoboost it was two, one for each valve cover. There is debate on whether you need two or only one. This is where researching how your vehicle's PCV system operates is important. For the Ecoboost engine, the system vents through the passenger side valve cover when the engine is not under boost (idle, lower RPMs) and vents through the driver side when under boost (accelerating, higher RPMs). The photo of the two bottles shows what my cans captured after about 1000miles of mixed driving (majority of it was highway). The bottle on the left is from the passenger side can (it was mostly oil and combustion vapor condensate) and the one on the right is from the driver side (about 50/50 oil/combustion vapor and water condensation). Now, I am sure that I am not capturing 100% of the vapors but I am satisfied with what I AM capturing I am getting the majority at least. I am giving this kit 4 stars due to cheapness of the clamps, hoses and thread tape (but what do you expect for $26) as well as the lack of instructions, but overall I am happy with the can itself. I will note that I was not able to figure out what the O-rings were for.