A power cable connected directly from the battery to the ignition points, reduces misfiring and increasing spark plug firing power
http://tmworks-web.jp/products/dph_eng.htm

It's plug and play, so if want to send car warranty can easily remove.

I'm wondering... why the sellers selling these kind of products never have a dyno graph to show? Each dyno only cost around rm300. I am sure they can afford it to give more confidence to buyers.

Stock to stock, the 'New' Persona beats the City by a large margin when it comes to handling. If you really want a good drive from the Persona, i'd suggest getting the Manual variant at 46k, then mod the hell out of it. Add GAB suspension 2k, front strut bar and ARB around 700, 2k for touch screen head unit+reverse camera, change to 16x7j tires/rims 2k, direct power harness 600, conlanfirm it will handle way better than the City, and it'll still be cheaper than the Premium Persona. Another thing about getting the Manual variant is that its lighter than the Premium version

True, but if you get into minor accident, and don't want to touch insurance, it will be painful to replace it out of pocket. You'll need to change the whole headlight set instead of the required components like the old days.