When I add a sub, I'll have to add another Amp.. Hopefully, the Amp will be smaller, (as I would still like some trunk space that didn't put out heat

I know its not the best setup, but I'm thininkg that I will mount the amp to my sub enclosure (so that I can remove them both when I need the trunk space)... I'll just have to make a very sturdy (and dampened wher the amp is to go) enclosure...
Cheers,
Tom