I am going to preface this by saying this is NOT a fully integrated solution. There are a few compromises and it does require a little bit of technical tweaking. But, if you want CarPlay without ripping out your headunit or spending a ton of money, this solution may work for you.

What you need:
1. An android Tablet. I found that a smaller one works better. I had a 7inch Samsung tab laying around that was repurposed.
2. Wireless CarPlay adapter, 3. micro-usb to usb female adapter (see #3 below)
4. stereo audio 3.5 cable ( )
5. tablet mount cup holder

First some background. MOST if not all car headunits run some implementation of an Android OS. CarPlay is an app that runs on top of it. If you install the app on an android OS you can run CarPlay.

The process is pretty simple. the wireless CarPlay adapter comes with a link to the software. It requires a little bit of set up and picking your options. Afterwords, you plug it all in and then you can either plug your phone in directly or do it wirelessly.

The way you plug it in is fairly straight forward.

car audio input <---stereo cable--- Tablet ---micro-usb adapter---> CarPlay adapter ---optional lightning cable---> iphone
If you want wireless, you have to pair your iPhone with the adapter.

Lets start with the CONS:
• There are a bunch of cables.
• It isn't fully integrated into the car.
• There are a few hiccups(like I haven't been able to implant OTG USB charging (see #4 below).
• PolarizedSunglasses may interfere with the tablet display.
• Unless you change the time out, display could turn off.
• You shouldn't any security/password for easy of use.
• Sometimes it doesn't auto connect.
• Sometimes the audio doesn't come out right.
• Navigation may not have voice over notifications.
• If you do it wired, your phone charges off the tablet.
• YOU MAY NOT WANT TO LEAVE IT PLUGGED IN WHEN YOU LEAVE THE CAR.

PROS:
• Cheap solution. If you have to buy everything (and use a fire tablet) you can do this for $150-$200
• Despite the long list above, 90% of the time it works perfectly,
• Can be implemented quickly without taking apart your dash
• Resting your wrist on the gear selector put you at a perfect angle to interact with it.

NOTES
1. Android Auto: This supposively also works with AA. I haven't tested it, so I can't comment on it.
2. Larger Tablets - I first tested this with a friend's 10.1 Samsung tablet. It was glorious.... but ultimately flawed as it was too big. A 7 is great. There is also a 6 inch VIzio on amazon that should work, that is the size of a large phone.... which is about the same size as the CarPlay area on a fully integrated mini. This could be used with a cravenspeed mount.
3. Micro-USB to USB Female: This is only needed if you have a tablet that has micro-usb (vs usb-c). Preferably, you should use... (#4)
4. OTG USB (on the go) - Some tablets allow you to use a y-splitter to charge and plug in a usb device. Apparently the Samsung I am using either doesn't support it or the cable I am using is a piece of junk. As a result, the tablet does NOT charge while in the car. This feature is a work in progress.

Conclusion: For me, I eventually plan to replace my headunit. This is just to tide me over until I am ready to pull the trigger. Hopefully this helps someone else. Let me know if you have any questions.

 

I'll have questions when you replace your head unit. I have the basic lcd h/u in my car so If I want any of these functions I just use my phone. Not ideal but it works for now.

Only thing I don't like with what you did as that I don't want to be looking down when driving. I thought about doing similar but mounting floating above existing h/u. I have a spare Samsung 7" awaiting the energy to proceed with project. Main hiccup is the mounting point.

 

I agree that it isn't the ideal place to have it. I am still debating a better place to put it in the mean time. But it is safer then using the phone as most things I can control with Siri.