-Engines and engine parts
-Drivetrains/Transmissions
-Exhaust
-Induction
-Electricals/electronics
-Gauges
-Engine managements
-All other performance upgrades for the engine
After using the Battery-free smartag that I DIY'ed before, I find it kinda
annoying and difficult especially if suddenly need to use the Smartag.
So, now I remove the wire and DIY a Switchable smartag that still use a battery. however, the battery will consume 0mA when it is switched off, therefore make it last longer.