If you hold an interlock condition licence and drive without using an alcohol interlock, you risk harsh punishment if caught. That can include hefty fines, licence suspension, vehicle impoundment, and conditions of your alcohol interlock licence by not using an interlock device.
Avoid the temptation of 'quick nipping down to the shops' in a vehicle without an interlocks; it can result in serious consequences. If you're caught, you'll spend more on fines that you would your entire program. Your relicensing will also be put on jeopardy, causing you to be on your program for longer.
For those who find participating in the program is too expensive, there are better alternatives than illegally driving a vehicle without an interlock installed. Ask your state authority about any financial hardship schemes you're eligible for. Driving illegally will cost you far more in the long term, with fines and vehicle impoundment a real possibility. participants that present a valid concession card are entitled to discounts. Driving illegally will cost you far more in the long term, with fines and vehicle impoundment a real possibility.
The laws are very clear; you may only drive a vehicle which has an interlock installed in it. It might not always feel convenient, but it's not worth risking the alternative.