It's be interesting if they were offered a cut of the damages. That would create a pretty crazy incentive structure.
I don't believe they do in general, and without having a bigger understanding of a lot of things, a lot of individuals are prone to magical, conspiratorial thinking, lacking in rigour.
For VW, you have very smart people, very self aware (i.e. able to read their own data), probably smart enough to snoop out what the law is, backed by an institution with integrity.
It's a classical case Whistleblowing type findings of the good kind.
'Random Employee Bob' may have access to a treasure trove of data they think is 'evidence' when in reality it's nothing of the sort.
Case and point: Manning with the cable leaks. Manning did not know what was on the cables, and turns out, there was nothing damming in them.
The other leak at the time - the video showing the deaths of freelance journalists probably isn't 'evidence' either. It's a shocking video, but the military misidentifying armed, unknown, unregistered individuals in a war-zone, moving towards friendly forces ... is a tragedy but probably not a crime. Though that leak is more contentious.
There are a lot of confused people in the world, who misconstrue their ideology for the more commonly agreed upon versions of what is right and wrong, and vast numbers of individuals in the press who are as much suited to narrative as they are to truth.
If you hop onto OAN right now, you'll see a delightfully despicable and shocking number of individual 'whistleblowers' who have 'evidence' that the election was 'stolen' by nefarious parties, and millions of people reading it believing that it's true.
Their incentive is clicks, Rudy Giuliani's is his pardon, or $20K/day. Which is why I implied 'crazy' incentives ...
It takes 'rigour' to counteract one's own impulses which usually amount to things like 'I disagree with the war, it was wrong, ergo, any leaking regarding it must be whistleblowing' - or - 'I agree with the war, therefore any leakage is treason'.
Manning 'cable leaks' exposed no US crimes, not even any wrongdoing on the part of the US and the questionable nature of 'whistle blowing' is compounded by the fact that he didn't even know what he was leaking in the first place.
Manning's 'exposure' didn't result in anyone being prosecuted except for himself, which was done by law (under a 'Democrat' political regime FYI).
Just the opposite, it demonstrated a US diplomatic corps trying to do a their very difficult and grinding jobs in a very complex and totally corrupt Middle East political situation.
What was the result of the leaks?
Mass protests against America?
No - it was the Arab Spring - Arabs on Main Street protesting, and in some cases overthrowing their own governments - because they were informed by the cable leaks.
So Manning, upset with his own government, leaks 'private information' - which materially has the opposite of the intended reaction: highlighting US diplomatic corps doing their jobs - and the entirety of the ME in deep corruption - highlighting the very underlying cause of external intervention in the first place.
The populist narrative of Manning being an absolute whisteblower is clearly wrong, mostly promoted by those who simply hate the fact the US was involved in a military capacity.
If Manning is a hero, it's to Tunisian and Egyptians, not to Americans.
Edit: for an example of material 'whistleblowing' relating to the war in Iraq, refer to Joe Darby [1], i.e. Abu Gharib.