[Nexus 7 (2013) General] snake2332:
I just got a Nexus 7 (2013) and threw an M rom on there and rooted it with the toolkit. It has such great standby battery life that I don't need to force-sleep the Nexus 7 with tasker when I turn the car off. I just have it go into airplane mode and let it go to sleep after 30 seconds by itself, so I would just get rid of the forced standby task if I were you. I was gone for 6 days and it went from 100% to 72% in standby, which impressed me. That's like iPad numbers...well maybe not. An iPad would probably still be at 94%, but screw iPads (sold my Air 2 cuz I just never used it). I drove for like 70 minutes today and it made it back up to 90% using a 2.4A USB port on a power inverter (screen on the whole 70 minutes, and wifi streaming to bluetooth, and GPS used by 2 apps).

However, what if you put a "wait 3 seconds" exit task in your Tasker "state"? Then it wouldn't exit the state immediately and it would abort the exit task once the state was restored, wouldn't it? Or would it complete the exit tasks even though the state was restored before the 3 second wait was done? I'm still a Tasker newb but manage to automate everything to my liking (Galaxy S6 connects to bluetooth of Alpine head-unit, turns on hotspot, Nexus 7 is screen-on when charging, comes out of airplane mode after 15 seconds to allow my phone to connect via bluetooth to the Alpine first [Alpine gets confused if Nexus connects via BT before my phone], Nexus launches speed-controlled volume app so I can manually enable it since it never does it automatically, Nexus enters car mode and goes home to Car Home ultra, Nexus resumes playing whatever music I was using last, etc.). Gotta love Tasker!

I was disappointed that TabletTalk didn't work. It even has "hotspot" mode, but it refused to find my phone from the Nexus. Maybe it doesn't work with Android M...oh well. I refunded the $3 app and figured I shouldn't be texting from my car even on the Nexus. For phone calls, my Alpine head-unit handles it...and I never get calls these days anyway, it seems.

Now I'm setting up a laptop since you need Windows to really tune and monitor a Subaru properly. Torque is handy for some stuff, but it can't do what RomRaider and ECUFlash can do. I'm using Splashtop Streamer to treat the Nexus as a 2nd monitor for the laptop, using the S6 as a router basically. Laptop has a BIOS option to turn on when AC power is applied, so it boots up automatically. That's really nice since it's going to be under the passenger seat. From hibernated state and running Windows 10 (4GB ram, i5-3210, Samsung 840 EVO SSD), it goes from power off to desktop in around 7 or 8 seconds. I have a Logitech K400 keyboard/trackpad that I think will fit in my glove box for when I really need to do work on the laptop, but the Windows 8 Touch mode in Splashtop works pretty well - minus the crappy on-screen keyboard.

For dash-cam purposes I just window-mount my Note 5 (work phone) and use a free dash-cam app. This is handy when I want to drive around like an idiot. I could sync the video with the front-cam video of the Nexus 7 that shows my face, though my ugly mug would ruin any cool video...

All in all, I have only spent around $200 (free laptop, Nexus 7 was $93 sold as 16GB but is actually 32GB, $35 power inverter 400W, $70 for dash-mount kit for single-din in my 2006 WRX wagon limited that came with the Alpine head-unit). Need to add a sub-woofer still, but going to go cheap and get a $130 all-in-one solution since I don't need to rattle people's cars around me.

Fun stuff!