Can I Target Models in a Transport?

[Styles]

Can I target a transport and also the models within, but can only actually attack them if the transport is destroyed?

 

For example I have a unit with lascannons and bolters. I target the transport with the lascannon and the bolters at the occupants (even though I currently cannot see them). The lascannon blow up the transport and I then can shoot the occupants with the bolters as they are now visible. But if the lascannon did not destroy the transport the bolter shots are wasted?

[Jolemai]

No. A unit declares a target at the same time, in this case only the transport is visible. If the first weapon you roll pops it, then that's that and another unit will need to target the surviving occupants.

[Xenith]

As above. All of a unit's shooting is simultaneous, and as per Jol, you have to declare targets before you start rolling. As the unit inside the transport is not an eligible target, you cannot declare it as one.