Sorry, but you are wrong. The holes are vents to allow air to fill the
area BEHIND the speaker, so that the speaker cone itself doesn't distort.
A cabrio trunk leaks more than enough air to allow this. If you need an
example, think large 6x9 speakers in the rear of most sedans. The back of
the speaker does not need to be "vented" to the passenger compartment, and
more than a speaker in the door does