If you like it buy it but from what you describe it isn't very impressive.
2 years old car he wants to sell plus the price isn't really cheap for a used car, you're probably losing out on the interest rate there. There are Myvi's with lesser spec you can buy new with new car interest rates, why not choose those?

1. Audio System 4CH amp? What kinda Cap Ayam brand is that? Never hear before. Beware of overheating or it messing up your electric wiring because it seems to me that it doesn't have enough channels to support 4 speakers and an active sub.

2. Front and back speaker sounds like just replace the 2-way/3-way originals with branded ones, would have been better to just get a component set.

3. How many inch is the subwoofer? IMHO American Sound nothing special.

4. They could be ULTRALEGGERA or Works Emotion CR-Kai.....replica's are only replica's cheap stuff. A set of 15" replica rims and decent tires can be had for RM1500-2000, some people get bored and change after 2 years the whole set.

5. It would be Llumar or Vcool when the car goes for JPJ inspection they going it tear it off no matter what, so don't get too attached to it. Make sure the warranty got cover such things and give you a free replacement else it isn't worth anything.

6. Ultra Racing bars unless you really have the horsepower and bend corners alot you ain't going to get much benefit from it, IMHO dead weight.

2012 Perodua Myvi SE 1.5 - as you can see you can get cars younger at the same price, so you ask me if it is worth buying your friend's car? I think not so.