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Properly profiled media lasts up to 3 years outdoors. The problem with vehicle graphics durability has to do with washing. The detergents used to wash vehicles can degrade a print without lamination.
There are two power buttons on the device, like other Roland inkjets, and the main power in the back must be left on so the machine can clean itself. This is power saving mode, which is energy star, but it still uses an internal clock to perform maintenance cleanings. If this is done, the machine can be left to sit for weeks.
The BN-20 prints as well as the VS VersaCAMM and has better print quality than most of Roland's existing fleet of inkjets. If you're just starting out, this would be a good machine for you.
-Dana