They both apply, even to single-crewed vehicles. The rule in the book has been FAQ'd. Due to laziness on the part of your's, truly, the FAQ has yet to be posted. Suffice to say that both single- and multi-crewed vehicles are entitled to the +3 RC bonus when not moving during the action. Therefore, a gunner on an Orca that fires while the Orca is not moving gains the +3 RC, but is, still, subject to the -3 RC inherent penalty, producing a total bonus/penalty of 0.
Does this answer your question?