Most of the Aro owners around here don't have their car prepared for long jurneys/ expeditions. Romania is not a big country, and most of the Aro's around here never leave the country

so there's no reason for investing money and time in these modifications. Of course you can find on this forum technical / mechanical improvements that may be usefull for a long journey, but otherwise, you should get your inspiration from the owners of LWB offroaders such as Defender 110, Patrol, the classic Toyota "troop carrier", etc.
And one personal note: since the 328 Maxi is such a big/ long car, you should try to accommodate sleeping bunks inside the car, in the rear, and not try to spend money on a roof tent - that is ussualy expensive or difficult to build your own. The main idea is to try to organise very well the rear part of your car's interior, by creating a list of every thing you need to carry and trying to find the best place for each item. So first, you need the list of every thing you need

you may include a spare battery (or install a auxiliary one, for electrical accessories) and even reserve some space for spare parts (since Aro is not the most reliable vehicle ever created

)