My daily driver from December 2013-March 2017 was a 2009 (generation 1) Mazdaspeed 3 in Metropolitan Gray Mica. It's currently for sale - contact me to inquire.
Right now, the motor is mostly stock, but when you look at what it comes with, you'll see why:
I've made the following modifications thus far:
The following are planned once the budget allows:
It came with the BOSE sound system, and I dislike BOSE, so I replaced the amplifier and speakers and added a sub, as follows:
The wiring job of course looks like it was done by a networking major. A specific wiring harness, Metra's model 70-2003, says it's made for GM vehicles but also functions as the "amplifier" side of the BOSE audio feed, meaning I was able to build a harness that plugs directly into the OEM connector. Buy two - it only comes with 14 pins and you need 17.