Here is my fix for the slow boot time and short car stop problem. I had most of these parts leftover from a car PC project. Use at your own risk.
What it does:
1. Starts boot up of radio when the car is unlocked
2. Lets the radio survive crank when the engine is started
3. Delays shutdown of the radio when the car is turned off (adjustable from 1 sec to 60 mins)
Parts:
12V SPDT Bosch type auto relay
1.3AH 12V SLA battery
ELK Delay Timer/Relay (ELK-960)
Two 1A diodes
Fuse and fuse holder
12V SPDT auto relay hook up:
The 12V SPDT auto relay, SLA battery, and fuse are all