Vapour-Like Smoke From the Exhaust

[ALFAitalia]

Maybe.....but how come they don't after more than a couple of miles on most cars.......?

 

[Bellow]

A petrol engine creates water in lockstep with petrol consumption ie, one gallon of petrol burned releases one gallon of water. Less for diesel, more with LPG - it's the hydrogen content that creates water.

It's C-class 2 litre patrol with two exhausts and the second one is not fake.

You can see from this angel the second exhaust produce a lot less smoke than the other one

The probability of this being a 'true dual' system is remote so the idea that you are witnessing two halves of the engine behaving differently is similarly remote. For more on what's occurring you might want to trace the pipes and see where they diverge and see if there's duplicated components that could cause this though I doubt that there are.
If there are still doubts as to smoke or condensate, capture the output (eg inflate a bin liner) and if condensate it should be wet and tasting it will show it to be flavourless water. Smoke will be dry and have a smell. Smoke invariably has colour - black when it's from fuel, blue from oil. White (on a petrol engine) is invariably condensate. From the fuel or an internal engine problem is the remaining question.