I was thinking about using this sub in my MINI (it is a sub and amp all in one).
Sub: I would still need a cleansweep and gauge wires. So what kind of cleansweeps have you used and what gauge size would I need? Also, where are the rear speaker wires located so I can connect the cleansweep to the rear speaker wires? Thanks!

 

Read the Integral Audio sub install instructions on their website.

You can either tap into the wires in the drivers footwell, or you can tap in at the factory amp, behind the drivers side rear hatch cover.

 

First of all, you'll love this MTX RT8PT. I have it in my MCS and gives a nice bass inside. Very impressive for the price of $127.
I replaced my rear speakers and found that they are rated 15 Watts each only and 5 (five) Ohms, no wonder many in the forum claims that rear "sucks" and wrongly blaming the OEM non-HK Alpine rear output cuts off 100 Hz.
If you can remove the back panel, try to disconnect the rear speakers (weak link) and use it as line source for the powered sub. That way, you can still use the fader function of your oem cd receiver and also max the voltage input to the sub.
Why do you need a clean sweep?