Do you really want the computer to turn off automatically every time you stop for gas or coffee?
My computer is in the trunk. I have a switch to power the inverter on and off located on my dash and, like you, have set the bios to always restart the computer when receiving power after power loss. It's awful easy to just switch on the inverter power from the dash whenever I want to use the carputer and to switch it off when I'm finished. That way I can stop for coffee, gas or even an hour or two of shopping and not have to restart the carputer when I return. I know some inverters will cause a computer reboot on ignition, but mine does not - I can start the car without interfering with the computer.
The only problem with this setup is that I need to remember to power off the inverter at the end of the day or I'll wind up with a dead battery in the morning. I understand that there are inverters available that will power themselves off automatically when they sense a low-voltage situation, which would solve the dead battery problem, but I don't use one. I do have a jump-in-carry with me, though, for those times when I screw up.
Anyway, I probably haven't told you anything you don't know, but it would drive me nuts if the computer shut down every time I turned off the ignition.
Well, thats what the timers on the shut down controller are for. You could easily have it set to shut down after say a half hour after the ignition has been turned off. This would give ya plenty of time to stop and get gas, or stop at the store to pick something up. This would also not be a problem with running the battery dead on the car, as a half hour is no problem.
Also with the remote start (I spent a bit of extra money for that when I had the alarm installed) I want the ability when I am getting ready to leave the house, to start the car with the remote like 10 minutes before I leave or so. This will give the puter it plenty of time to boot up, and then sync to get the latest weather, traffic and such by the time I get to the car.
The same works when coming out of a store, I start the car when I walk out of a store, to get the A/C going and the puter booted up by the time I get to the car.
Just by chance anyone is watching this thread, a new Meet is planned in West Palm Beach at this link for July 29th 07'