Guys,
before you buy anything try running the air con at full blast on full heat with the car idling for around 5-10 mins - this usually burns out the bacteria and the smell will go away. Its a massive issue on renault cars and this solves it everytime.
Give it a try at least its free.
If you do use the spray or bomb, you drop it in the passenger footwell and run the air con on recirc so it gets sucked through the system
hope this helps
P