Howdy!
According to RAW (EotE pp 226) no defensive zone on vehicles may have more than 4 points of defence, so there's a cap on 4 setback dice per zone (derived from defence! Other sources of setback dice is in addition of course).
How do you interpret this rule? I mean, there's a 3 adv result that can provide +1 defence (to one zone arguably) for 1 round (if you're liberal enough to apply that from personal combat to vehicle combat, and just for the sake of argument, let's say it's kosher), would you allow this to break this cap? What about talents?
Would you apply a similar 4 point cap to personal defence?