I apologize it's taken me a while to get back to this. But want to bring back my findings.
The good news.
It works and works exactly as wired, with only one issue I'll detail below. Things of note. Audio quality is recognizably better than using simple Bluetooth. Better bass, and better clarity. Across the board better audio experience than with Bluetooth alone. I should have tested it against wired but I haven't sorry. The connection I didn't time against a wired connection, but there was no reason too. It connects and starts playing media fast. If not as fast as wired, it's damn close. This was not the case with my testing of the CarlinKit 4.0 last Fall.
Setup was pretty easy. I did note one thing during the initial setup. It wouldn't connect. I did an over-the-air update and that completely resolved the connection issue. AAWireless ought to perform the update as part of the setup. When I got the unit originally, it defaulted the Wireless to Auto, which I had issues with and had to manually select a dedicated channel. Since that time AAWireless has updated their software and it now defaults to Channel 149. No longer Auto. Auto would frequently jump channels and cause audio hitches when it would do so. Personally, I use Channel 165. Only because that's what I used when it originally defaulted to Auto, it worked then so I kept that setting even after AAWireless changed the default. I do use some custom settings, I'll go over that in another section.
Here's how it looks with a replacement cable bought from Amazon Canada
and some Velcro strips from the dollar store. The dual 90-degree bends allow the cable to tuck out of the way so the center console is still usable, not the case with a straight USB cable which basically gets in the way of anything being put in that location. It does block the left hand ... I can't even remember what's there, probably the cigarette lighter thingie maboober. The 90-degree bend cable is available with the bend going the other way, decide which port you want to block before purchasing. The location of the unit does not block my ability to place my largeish Samsung Note into the charging tray. The charging tray does not appear to impact performance or audio quality in any way.
On to the problem
I've had a lot of frustration with this thing, to be honest. More than once wanted to chuck it out the window. What has gotten me past that feeling of frustration is the simple acceptance that the one issue it has isn't correctable and living with it. I spent months trying to find a configuration that worked. I worked with the amazing team at AAWireless and they are good and responsive, so kudos to them. But the issue I'm experiencing just wasn't correctable. Is the problem the AAWireless? More and more I don't think so. It could just as easily be my Samsung Phone, the KIA Infotainment unit, or AndroidAuto itself.
The problem is this. And I'm convinced it has to do with KIA's idiotic idea that an always-on USB makes sense when it absolutely doesn't. 95% of the time the combination of my AAWireless, Samsung Note 9, and KIA Infotainment works flawlessly in every way as though my phone were plugged in wired. But there is a small hitch. In situations where I turn the car off and leave the car for a short time, and don't go outside the car's range, for example stopping somewhere to pick up take out. I'm out of the car for less than 5 minutes, within wifi and Bluetooth range. In those scenarios, I'll return to the car, the phone will connect, I can manipulate AndroidAuto from Infotainment, but audio plays from the phone's speakers, not the car's.
It's consistent. I can anticipate now when it will happen, like every time I stop at Subway to pick up food, and I run the little fix I've found before I even put the car in gear. Yes, it's frustrating. But depending on how often you stop for take out you may not come across it. I tried a lot of things to get it connected again. Unplugging the AAWireless and plugging it back in, sometimes worked but not consistently. Rebooting my phone generally resolved it but took too long. The fix I found that fixes it every time is to 'Force Stop' AndroidAuto on my phone. I do it nearly blindly now and it's not a huge deal.
Settings | Apps | AndroidAuto | Force Stop | OK
That will close AndroidAuto, your Infotainment will disconnect and AndroidAuto will automagically restart and reconnect normally. Irritating, yes. But it is only in very specific situations as mentioned above. So much so that I can anticipate when it's going to occur.
AAWireless's recommendation for this is enabling a setting called 'Start/Stop', which was implemented specifically for vehicles that utilize an always-on USB like KIA. I experimented for a month with this, and at times it would work flawlessly for a week at a time but ultimately always seemed to lead to a more serious failure down the road. A more serious failure was something that required a complete reset of the device.
My settings (the things I changed).
Changed to MTP with retry.
Changed this on the recommendation in one of the forums. A user said he found things to be faster and more responsive and I found that to be the case as well.
Changed to 165.
As mentioned before, Auto doesn't work, but they've since changed the default to 149. You likely won't need to change this.
This is a recommended change from AAWireless for always-on USB.
I experimented with this a lot but found when I did it always lead to bigger issues.
If any of you find settings that work, let me know so I can give it a go.
Living with it.
It's a pain in the ass. That one problem. But I've learned to live with it. And that one time in twenty when I get in the car and have to 'Force Stop' AndroidAuto, for me is worth the 19 times I got in and it worked flawlessly.
Keep in mind, I can't confirm where the blame lies. Maybe it's the AAWireless, but having interacted with the team there and seeing how seriously, and personally, they take problems in some of the support forums, I'm convinced they've exhausted everything on their end. Could be the KIA's always on USB, it's certainly the root of the problem. If only KIA didn't do that this would be a non-issue. We can't rule out Samsung either, the AAWireless guys have commented in forums that Samsung just does things their own way and don't always follow the recommended implementation of things. For that matter, AndroidAuto could be the culprit itself, being that restarting it appears to correct the issue. Who knows.
I've detailed where the issue lies. Short stops, where you don't leave the range of the car's wireless and/or Bluetooth. If you're interested in one of these, decide for yourself, how often you end up in that specific situation and make the decision as to whether or not you can live with the fix.
The CarlinKit 4.0
I've got the CarlinKit 4.0 as well. That one didn't go well when originally testing it last Fall. Very slow to connect. No over-the-air updates, which makes it a pain to update. Very little for settings and difficult to work with. And it didn't give the same experience as wired, whereas the AAWireless does. The CarlinKit stretches the screen without split screen. I'm considering doing a fresh update to mine and re-evaluating. So you may see a similar post for that in a few weeks. I sometimes get the impression that the device connected to Infotainment as CarPlay and performed some kind of conversion for AndroidAuto. Not sure. They'd have to fix a lot for me to reconsider it. Last time I looked at it was December. Will see.