My suggestion: quit worrying about it.
I want to put a 10" sub in my trunk along with my carputer. Does anyone think this is a terrible idea? Will it mess up my hard drive? Or anything else? I don't want to put the computer any where else and I really want to put this sub in my car also. Suggestions?
I have both of my pcs in the trunk, along with 2 12"s, an amp rack with 4 amps, and my RF symmetry signal proccessor. I have had no issues with any of them. Summertime here in Florida it does get a little warm in the trunk, but I leave the trunk passthrough open and the heat gets replaced with ac. On the upside, during the winter the back seat passengers feel like they have heated seat backs.
For the moment until I get my molded glass boxes done I even have the pc rack unit above the speaker box. That is not where I would recommend placing it but that was my only option as the rack is a 2u server rack and too large to mount any place else. If you mount yours on the floor or someplace away from the speakers you should not have any worries.
Just make sure that the PC case doesn't press against your sub box. I'm pretty sure that's how I killed my first hard drive. Its temporary replacement has had no problems whatsoever for the past several months (and it's probably about 10 years old). I've got two 12" subs a few inches from my carpc, and don't play them quietly.