DMP3A works fine in PARTY MODE, but HDD doesn't spin up in the ALUCARHOST.
This symptom indicates power problem, an unwanted voltage drop in the power circuit. Check the ground cable of the ALUCARHOST and the red +12V wire. In case of problem, use thicker cables and look for a better grounding point. Depending on the installed hard disk drive and the car battery conditions HDD do not spin while car engine is not running.