IB = ten times vas.
Trunk holds say 300-400 L (leaks like a whore too.... and that combined with the flexing = terrible sound quality)
So what driver do you know has a vas of 30-40 L?
If you went by the 4 times definition you might have 80-100 L Vas at most. But at that point you're better off going sealed.
When no one states their GOALS nor the BUDGET then I dont see any point in providing a massive list of suggestions.
As far as I'm concerned, those tens would be easy to install. Just as they're not too expensive as far as i'm concerned.
But again, there are no clearly defined goals so we can all suggest whatever we want and it wont help the OP anyways.
Its like those stupid "What parts should i buy for my car to make it fast" threads. No goals, no budget, no help.
Edit: official count is 453 litres in the trunk.