Hi guys, my dad installed some minor set up in my car for quite some time already. Btw, my car is AE111 corrolla. I check the amp below the seat and it is written Nickel Auto HiFi amp 150 watts x2. Do anyone know this brand? My HU is JVC KD-R306. If plan to upgrade, which should I upgrade first. I only use Aux therefore touchscreen and Bluetooth is not necessary for me.