the car will be fine.. bring a cuision.. your ass might get sore =P..
Yes, bring cushions as the seats were not really designed to be sat on for a very long time and can be quite uncomfortable after a while as you cant move around in them.
I bought my vtir from Melbourne and drove 8-9 hrs to Adelaide, road quality is quite good all the way, just like any other car, look after it and it'll look after you. You may want ear plugs though.
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