Present Perfect Tense in Passive Voice with 'just' -- Can any native teacher explain?

[numberone]

Hi teachers,
I'm not a native speaker. I have 2 questions here which really confuse me.

Which one is correct and more natural?

1. Present Perfect Tense in Passive Voice with 'just'
Active : They have just finished the report.
Passive : The report has just been finished by them.
or
The report has been just finished by them.

2. Present Perfect Continuous Tense - Passive Voice
Active : John has been driving that car for 5 years.
Passive : That car has been driven by John for 5 years.
or
That car has been being driven by John for 5 years.
( This sounds so unnatural, doesn't it?
Can we use Passive Voice in Present Perfect Continuous Tense ?)

What about ?? - 'They've been working in this company for 2 years.'
Any advice with good substance?

Thanks in advance ^____^

[David L.]

1. Present Perfect Tense in Passive Voice with 'just'
Active : They have just finished the report.
Passive : The report has just been finished.

(Note the omission of 'by them'. Its inclusion makes it sound very unnatural. The Passive voice places the emphasis on the fact that the report is now finished, not on 'by whom' - that's the function of the Active voice, emphasizing the 'doer', the performer of the action.)


2. Present Perfect Continuous Tense - Passive Voice
Active : John has been driving that car for 5 years.
Passive : That car has been driven by John for 5 years.:YES - The sentence sounds like someone expressing exasperation or something. Usually, if the 'doer' of the action is to be mentioned, then use the Active voice: John has been driving...
In that form, where you are including the 'doer' in the Passive voice construction, it would be something like:
That car has been driven by a little old lady on weekends, so the mileage is low.

or
That car has been being driven by John for 5 years.
( This sounds so unnatural, doesn't it? YES - and doesn't make sense.
Can we use Passive Voice in Present Perfect Continuous Tense ? NO

What about ?? - 'They've been working in this company for 2 years.'
YES.

Now, why 'NO' for the Passive voice?

[numberone]

Hi David!
Thanks for your clear explanation here ^_____^