the sub it is NOT installed in any enclose.. ii does use the space behind the panel. The panel is a plastic and is still moveable... you can see the handle from the picture....
That installation it is not ideal for the sub.... but I am impressed with the results.
As far as the ampli I never had heat prolem the thermal protection never engage. One thing I saw the signal from the radio is lower to avoid distorsion so I run max volume prior distorsion also with the sub.... so I think the amp is not running any close to max performance and I don't think overheating will ever be a problem.
Anyhow... worse case scenario the amp overheating protection will kick in...
I'll be here to help for any other question