4th Edition DF chart - Opportunity Fire question

[cjsiam]

So if I am reading the responses correctly, these would be the modifiers for different circumstances for Direct Fire Opportunity Fire:

• Op Fire (OF) vs. Standard personnel:  +1
  
• OF vs. AT, AA, Mortar, Cav, etc:  +1 for target being an AT, AA etc unit only (do not apply above).  Also,  I don't think that deployed or limbered should matter:  The reason being that a deployed unit isn't moving so it is not considered opportunity fire and the target is still an AT or AA unit so the +1 should apply in either case.
  
• Same for Artillery = +2 for either OF or regular DF but do not apply additional +1 from 1st bullet point.
  
• No OF +1 modifier for AFV or APC units. (I assume this would include Self-propelled artillery with an armor factor since by definition, it would be considered and AFV unit and so would not fall under the second bullet?
  

Now that the discussion has started,  I guess the question is do Trucks and/or wagons (whether loaded or not) suffer the +1 Op Fire since they are not technically personnel units but Transport units?  Again this is  only direct fire OF as there is a specific modifier for Bombardment on loaded transports.  I think we have always applied it but now i don't think it should apply when following the letter of the rule.

I'm thinking this may not be right guys!....and this is not something I went deep before but----I think once a unit becomes "transported" you don't consider it AT/Arty...it's transport
that is fired at, not the unit transported....(AT/Arty)...

5.65 Taking DamageIf a transport unit is fired on, everything it is transporting suffers the same fate as the transport. If a transport must make a morale check due to enemy fire, make one roll for the transport only, adding the morale bonus of any one leader it is carrying or in its hex or an adjacent hex. If the transport becomes disrupted or demoralized or is eliminated, so does everything it's transporting.

So---there is no modifier +1/+2 for DF used in Op fire on AT/Art(respectively) shot at while limbered and being transported.....you get to fire on the transport...no OP +1, just a base
roll on the transport....

So while you CAN OP, you get no modifers to "moving in open as personnel" or "type of target--it's transport"

Show me where I'm wrong....