> Lubricate your power window rubber lining with non-oil based vinyl protectant every 3 months (I use Amorall)
> Check your alternator charge. Best if you have a volt meter.
> Check your battery connection.
> Install grounding (fake HKS cheap grounding around RM15 per set for 5 point grounding)
Airtrek alternator is weak. Mine has similar issue too when power window is operating, headlamp seems to dim a bit. Worse is when I pump my subwoofer, it dims even more (even dashboard light) and in-sync with the bass. So I don't trash the ICE during night driving.