I think not. The TCA is being changed as part of the vehicle's movement, presumably to the target the vehicle plans to shoot at. With fire in other phases the turret is pointed in a general direction but not necessarily the actual target unless the target is already acquired.Does the D2.321 bypass TCA penalty to fire apply to a vehicle during the movement phase (i.e. using bounding first fire)?
The +1 extra penalty only applies if the TCA changes to or through the side CA as part of the attack, as best I can tell. With BFF during the MPh the TCA does not change as part of the shot. It changes as part of the movement actions. All BFF shots must be taken within the current TCA, which change as movement actions. My read is that none of the side TCA penalties of D2.321 apply for BFF during the MPh.jrv - would your opinion change if the moving vehicle entered bp with "side" TCA (i.e. didn't change TCA)? D2.231 says the +1 penalty applies even if it does not change its TCA. However, under the Case A TH rules, C5.13 says Case A is never applicable to an attacker firing during his own MPh (my guess is this is referring to what you mentioned)..
It has to pay *the appropriate* Case A penalty, and by C5.13 the appropriate case A penalty is none. I think you could reasonably ask for a clarification on this, because I find it a bit twisty in my mind, but that is how I read it. Case A does not apply per C5.13, and the extra +1 does not apply because CA does not change as part of the shot."The +1 extra penalty only applies if the TCA changes to or through the side CA as part of the attack, as best I can tell"
But what do you think this language in D2.321 means: "A TCA based on a Bypass side Target Facing covers a potentially much larger Field of Fire (all hexes on that side of the firer between the front and rear Target Facings) and consequently must pay appropriate Case A (C5.1) penalties for firing within this enlarged CA even if it does not change is TCA"? Note that the italics are not mine, but within the rule.