I'm looking at picking up a stealthbox on ebay so I can get a sub installed in the t4r and keep all my cargo room. These fit 8" subs, correct? I already have an amp hooked up, running my components in the front doors. I also already have a fairly-shallow 8" sub. Can the stealthbox be installed fairly easily if I don't have the JBL system? It just needs to run to the amp, right? Are there certain dimensions for the sub that I need to stay within?