Right, car shoots usually for ~30-40Hz spl typically.
Would the beefed up motor help no matter what enclosure?
Yes, but far more so with small sealed systems.
In any event, I don't think it matter much. The standard car audio W7 has an huge motor system with incredible thermal power capacity and linearity. It works superbly in ANY cabinet system that is designed properly. I don't know of anything, at any price, that can substantially outperform a W7, and very few that are comparable. And while many people may say the W7is over priced, that is not so if you shop around carefully. You can purchase them for nearly 1/2 what they cost from a normal retail outlet if you are willing to give up a factory warranty(
JL will not warranty products unless purchased from vastly over-priced 'official authorized' dealers).
-Chris