don't confuse and anti-roll bar with a roll cage.
one (anti-roll bar) is to restric your car from leanng over in turns (suspensino part)
the other (roll cage) is to save your hide in a roll over situation and add rigidity to your chassis
the wait is almost over.... (and yes, i agree for dust the oiled cotton setup would be better)
as F1 said an oil bath would fail early on in the rally, however I think a 2nd paper/cotton filter would work but will be slightly restrictive, but worth doing on most cars without a snorkel or a good filteration system (dust is very fine & can slip past most cleaners)