Thank you for catching this. I just saw this on my echo as well.
It’s why I renamed all mine so I can have fun on conference calls with all those people who have default Alexa 
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Can you share your setup and how you did this? Very cool
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My car has t-mobile sync. It is basically in car WIFI + auto tracking. The alexa part is just Echo dot connected to the in car WIFI. The car has my arrival sensor which can detect when the car arrive or left my home.
I just install Echo speak. This is another component that is needed.
I have a rule machine that will read the status of my garage door when the arrival sensor detect "not present" status. In fact, I can send a check list for alexa to read to me on this event such as my fireplace or some critical appliance state. I can make my own decision on what to do. In some cases, I may want to let the fireplace run because I know someone else is in the house.
The Arrival sensor also detect when my car started. When this happen, I can have alexa start a music on my car, read traffic report and various others stuff before even leaving the house.
For simple car presence an induction loop in the floor surface would work great. I've installed a lot of these over the years for safety on automated gates, barriers and road blockers. It's just a rectangular saw cut in the floor/road surface. A thin wire loops around the cut several times (loop number prescribed by circumference) and connects back to a small controller. I've also made them in a plastic conduit frame and buried them in gravel or set them in a road/driveway prior to top coat going on.
The loop gives off a 0.5m radius field around the wire. Sensitivity is adjusted and then the controller will provide volt free relay contacts for pulse or latched change of the contact on detection or un-detection. The relay could be connected into a Fibaro Smart Implant or any contact that provides input terminals (Aeotec). This works much better than PIR's or active infra red beams. In the UK or EU many of the automated gate manufacturers such as FAAC do these controllers and they're not expensive.
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This probably a good setup if you don't really need to know which car is on the spot.
For me, the selection for the zigbee as presence sensor is for the authentication. This is one of the factor in my consideration. I would be opening my garage door to an authenticated car only. I do not want to have any car standing on a spot to open the door.
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This is awesome. I missed this post. I am interested should you have more boards available.
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If your phone is always in the car you could do the same with an Alexa auto instead of the dot
Are you referring to Alexa Auto device or your alexa phone app that goes into auto mode during a drive?
I have not tried both yet. I do not think these devices show up in my echo speak app. If you use echo speak and you see them, I am guessing that you should be able to do the same.
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alexa auto shows up as echo speaks.
Thanks for sharing. It is good to know. Btw, does echo auto support multiple phones? We share our cars within or family.
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Been playing with one of the prototype units as a car presence sensor. Works great--I'm so appreciative of this community and for @iharyadi specifically!
I'm still waiting for the project box to arrive from China so I can protect it and to increase in-car WAF. But that'll come soon enough. I've also yet to receive the motion sensor to replicate a faraday cage to proxy a contact sensor. Excited to see if I can get that to work.
Besides that, it seems really reliable for presence, car power, and vibration. Temperature is fine too. Waiting to test out the open/close car door event. Oh, I haven't yet played with the rechargeable battery either.
If I could pick on one small thing, it's the antenna. It is really large. I bought this one, which is linked in the thread above a couple times. Does anyone know if, ahem, size matters? Like seriously, is this antenna necessarily long and fat to work as a presence sensor out on the street?
To put it in perspective, look at the picture in message #19 in this thread. I have the antenna on the far left. Look how much bigger it is than the ones in the middle or right. Do I lose fidelity or performance somehow with a smaller antenna? As is, I don't know if the box will even fit in the center console of a large SUV with that mongo thing attached.
Any input?
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@mluck, Just disclaimer, I am not an expert at all on the RF side of things. I do not have equipment to determine whether one antenna is better than others. Previously, I am more likely to use a Zigbee module that come with PCB antenna. I let the manufacture tune and guarantee the antenna performance. For this sensor, I want to have the flexibility to install my own antenna. Therefore, I opt with a module that has external antenna.
My knowledge about external antenna comes from shopping for it and trying it out. Here is what I learn.
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the longer the antenna, the higher the gain.
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Watch out for extremely high gain antenna 9dbi or more. They could be directional. The gain may put the output in illegal range range as well. I typically look for antenna with 6dbi.
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If you don't mind with running cable to external antenna, you may get a better coverage. You will take a hit on the cable. Every feet of cable from and to the antenna, you may loose half of the power. But, having the antenna outside the car avoid the issue with faraday effect of your car. The net effect is actually give us a longer range.
One of the antenna that I tested is a short one. The following antenna has around 3db gain. Of course, the range is not as longer. But, It does work.
I hope this help you searching of your own antenna. Please let us know what you end up with.
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Cool do you have a link for that antenna or did you take of off a router?
I got mine from here.
Please double check your connector. I do not remember whether you have the sma or rp-sma. When I was looking for mine, I come across both type in Amazon
I have rp-sma. Would you suggest I use the the above BOOBRIE and get a rp-sma to sma adapter? Or is there a antenna for rp-sma natively?
I would avoid converter. This is just because if you are buying new antenna, amazon has all kinds of antenna. For example....
They looked like generic 50ohm 2.4Ghz antenna that should work with our modules.
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I just want to update everyone that the project is still actively on going. I am currently testing a batch of 10 to test the manufacturing process.
The new board will have temperature range to control charging process to make it safer to use in extreme temperature. There are some power consumption optimization during sleep time. There is also minor component substitution.
Here is an image of assembled module from the manufacturer.
The most important changes is that I am not assembling them. I have the modules professionally assembled by a contract manufacturer.
I do not have the modules on hand yet. However, they are really close to done. Based on this manufacturing test, we can make the module at larger quantity in the next batch.
I am asking for community support. Collectively, If get enough demand, I can produce the modules at larger quantity. This will make the module more affordable for all of us. I am looking for a way to get feedback on the demand for the next steps of this project. Please feel free to reach out if you have any feedback for me.
Thanks
Iman
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Any chance you can design a case and either sell it or permit us to 3D print it?
Also, put me down for one 
Thanks!
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